Thermoplastic composition

ABSTRACT

An extrusion composition containing at least one resin selected from the group consisting of polypropylene homopolymers, polypropylene random copolymers, and polypropylene impact copolymers. The extrusion composition also contains at least one phosphate ester-based nucleating agent provided in the composition at a use level of between about 0.01 and 0.15 parts by weight, in relation to 100 parts by weight of the resin and at least one co-additive selected from the group consisting of poly(ethylene glycol) and copolymers containing segments of ethylene oxide, wherein the co-additive has a number average molecular weight of about 300 or more, and wherein the use level of the co-additive is about 0.005 parts by weight or more, in relation to 100 parts by weight of the resin.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application62/795,818, filed on Jan. 23, 2019.

TECHNICAL FIELD

The present invention relates generally to nucleated polyolefincompositions having improved mechanical properties.

BACKGROUND

Numerous nucleating and clarifying agents are used as plastic additives.Several nucleating agents for thermoplastic polymers are known in theart. These nucleating agents generally function by forming nuclei orproviding sites for the formation and/or growth of crystals in thethermoplastic polymer as it solidifies from a molten state. The nucleior sites provided by the nucleating agent allow the crystals to formwithin the cooling polymer at a higher temperature and/or at a morerapid rate than the crystals will form in the virgin, non-nucleatedthermoplastic polymer. These effects can then permit processing of anucleated thermoplastic polymer composition at cycle times that areshorter than the virgin, non-nucleated thermoplastic polymer. Suchcompounds assist in optically clarifying plastics or otherwise improvingthe processing or physical characteristics of polymers in plasticproducts. Many plastic products sold and used are made from polymermaterials that contain nucleating or clarifying agents within thepolymer.

While polymer nucleating agents may function in a similar manner, notall nucleating agents are created equal. For example, a particularnucleating agent may be very effective at increasing the peak polymerrecrystallization temperature of a thermoplastic polymer, but such anucleating agent may cause different shrinkage of a molded part producedfrom a thermoplastic polymer composition (compared to a non-nucleatedversion). Such a nucleating agent may also be ineffective in increasingthe stiffness of the molded part to a desirable degree. Differentnucleating agents impart different levels of optical propertiesimprovements to the thermoplastic polymer compositions.

Given the complicated interrelationship of these properties and the factthat many nucleating agents exhibit less-than-optimal behavior in atleast one respect, it would be desirable to have a nucleated polyolefinthat also had good thermal and optical properties with increasedmechanical properties such as stiffness.

BRIEF SUMMARY

An extrusion composition contains at least one resin selected from thegroup consisting of polypropylene homopolymers, polypropylene randomcopolymers, and polypropylene impact copolymers. The extrusioncomposition also contains at least one phosphate ester-based nucleatingagent provided in the composition at a use level of between about 0.01and 0.15 parts by weight, in relation to 100 parts by weight of theresin and at least one co-additive selected from the group consisting ofpoly(ethylene glycol) and copolymers containing segments of ethyleneoxide, wherein the co-additive has a number average molecular weight ofabout 300 or more, and wherein the use level of the co-additive is about0.005 parts by weight or more, in relation to 100 parts by weight of theresin.

A masterbatch composition contains at least one resin selected from thegroup consisting of polypropylene homopolymers, polypropylene randomcopolymers, and polypropylene impact copolymers. The masterbatchcomposition also contains at least one phosphate ester-based nucleatingagent provided in the composition at a use level of between about 1 and30 parts by weight, in relation to 100 parts by weight of the resin andat least one co-additive selected from the group consisting ofpoly(ethylene glycol), and copolymers containing segments of ethyleneoxide, wherein the co-additive has a number average molecular weight ofabout 300 or more, and wherein the use level of the co-additive is about0.5 parts by weight or more, in relation to 100 parts by weight of theresin.

An extrusion composition contains at least one resin selected from thegroup consisting of polypropylene homopolymers, polypropylene randomcopolymers, and polypropylene impact copolymers. The extrusioncomposition also contains at least one benzoic acid salt-basednucleating agent provided in the composition at a use level of betweenabout 0.01 and 0.15 parts by weight, in relation to 100 parts by weightof the resin and at least one co-additive selected from the groupconsisting of poly(ethylene glycol), and copolymers containing segmentsof ethylene oxide, wherein the co-additive has a number averagemolecular weight of about 300 or more, and wherein the use level of theco-additive is about 0.005 parts by weight or more, in relation to 100parts by weight of the resin.

A masterbatch composition contains at least one resin selected from thegroup consisting of polypropylene homopolymers, polypropylene randomcopolymers, and polypropylene impact copolymers. The mast batchcomposition also contains at least one phosphate ester-based nucleatingagent provided in the composition at a use level of between about 1 and30 parts by weight, in relation to 100 parts by weight of the resin andat least one co-additive selected from the group consisting ofpoly(ethylene glycol), and copolymers containing segments of ethyleneoxide, wherein the co-additive has a number average molecular weight ofabout 300 or more, and wherein the use level of the co-additive is about0.5 parts by weight or more, in relation to 100 parts by weight of theresin.

An extrusion composition contains at least one resin selected from thegroup consisting of polypropylene homopolymers, polypropylene randomcopolymers, and polypropylene impact copolymers. The extrusioncomposition also contains at least one phosphate ester-based nucleatingagent provided in the composition at a use level of between about 0.01and 0.15 parts by weight, in relation to 100 parts by weight of theresin and at least one co-additive selected from the group consisting ofpoly(ethylene glycol) and copolymers containing segments of ethyleneoxide, wherein the co-additive has a number average molecular weight ofabout 300 or more, and wherein the use level of the co-additive is about0.005 parts by weight or more, in relation to 100 parts by weight of theresin.

A masterbatch composition contains at least one resin selected from thegroup consisting of high density polyethylene, linear low densitypolyethylene, and low density polyethylene. The masterbatch compositionalso contains at least one phosphate ester-based nucleating agentprovided in the composition at a use level of between about 1 and 30parts by weight, in relation to 100 parts by weight of the resin and atleast one co-additive selected from the group consisting ofpoly(ethylene glycol), and copolymers containing segments of ethyleneoxide, wherein the co-additive has a number average molecular weight ofabout 300 or more, and wherein the use level of the co-additive is about0.5 parts by weight or more, in relation to 100 parts by weight of theresin.

An extrusion composition contains at least one resin selected from thegroup consisting of high density polyethylene, linear low densitypolyethylene, and low density polyethylene. The extrusion compositionalso contains at least one benzoic acid salt-based nucleating agentprovided in the composition at a use level of between about 0.01 and0.15 parts by weight, in relation to 100 parts by weight of the resinand at least one co-additive selected from the group consisting ofpoly(ethylene glycol), and copolymers containing segments of ethyleneoxide, wherein the co-additive has a number average molecular weight ofabout 300 or more, and wherein the use level of the co-additive is about0.005 parts by weight or more, in relation to 100 parts by weight of theresin.

A masterbatch composition contains at least one resin selected from thegroup consisting of high density polyethylene, linear low densitypolyethylene, and low density polyethylene. The mast batch compositionalso contains at least one benzoic acid salt-based nucleating agentprovided in the composition at a use level of between about 1 and 30parts by weight, in relation to 100 parts by weight of the resin and atleast one co-additive selected from the group consisting ofpoly(ethylene glycol), and copolymers containing segments of ethyleneoxide, wherein the co-additive has a number average molecular weight ofabout 300 or more, and wherein the use level of the co-additive is about0.5 parts by weight or more, in relation to 100 parts by weight of theresin.

DETAILED DESCRIPTION

Many types of additives are used in thermoplastic polyolefincompositions for different optical and physical properties. The polymercompositions described above can contain other polymer additives inaddition to those contained in the additive composition. Suitableadditional polymer additives include, but are not limited to,antioxidants (e.g., phenolic antioxidants, phosphite antioxidants, andcombinations thereof), anti-blocking agents (e.g., amorphous silica anddiatomaceous earth), pigments (e.g., organic pigments and inorganicpigments) and other colorants (e.g., dyes and polymeric colorants),fillers and reinforcing agents (e.g., glass, glass fibers, talc, calciumcarbonate, and magnesium oxysulfate whiskers), nucleating agents,clarifying agents, acid scavengers (e.g., hydrotalcite-like acidscavengers [e.g., DHT-4A® from Kisuma Chemicals], metal salts of fattyacids [e.g., the metal salts of stearic acid], and metals salts of fattyacid esters [e.g., lactylate salts]), polymer processing additives(e.g., fluoropolymer polymer processing additives), polymercross-linking agents, slip agents (e.g., fatty acid amide compoundsderived from the reaction between a fatty acid and ammonia or anamine-containing compound), fatty acid ester compounds (e.g., fatty acidester compounds derived from the reaction between a fatty acid and ahydroxyl-containing compound, such as glycerol, diglycerol, sorbitan andcombinations thereof), and combinations of the foregoing.

When the term “extrusion composition” is used in the application, thisis referring to the polyolefin composition that is used to make finishedgoods. The composition is extruded (or blown, etc) into food storagecontains, toys, and other goods. When the term “masterbatch composition”is used in the application, this is referring to a polyolefincomposition that contains much higher concentrations of additives thantypical finished goods. This masterbatch is then mixed with polymer withlittle to no additives to dilute the additives to the desired amount fora finished good. It is typically easier and less expensive to use amasterbatch composition to introduce low levels of additives than itwould be to add them directly to the extrusion composition. Asmasterbatches are already premixed compositions, their use alleviatesissues with the additive clumping or insufficient dispersion. Theconcentration of the additive in the masterbatch is much higher than inthe end-use polymer, but the additive is already properly dispersed inthe host resin. The masterbatches can be fairly highly concentrated (incomparison with the target composition), with high “let-down ratios”;e.g. one 25 kg bag can be used for a ton of natural polymer. Therelatively dilute nature of masterbatches (in comparison with the rawadditives) allows higher accuracy in dosing small amounts of expensivecomponents.

As used herein, the term “thermoplastic” refers generally to a polymericor polymer material that will melt upon exposure to sufficient heat butwill regain its solidified state upon cooling. Particular types ofpolymers contemplated within such a definition include, withoutlimitation, polyolefins (such as polyethylene, polypropylene,polybutylene, and any combination thereof), polyamides (such as nylon),polyurethanes, polyester (such as polyethylene terephthalate), and thelike (as well as any combinations thereof).

Preferably, the polymer is a thermoplastic polymer. More preferably, thethermoplastic polymer is a polyolefin. The polyolefin polymer can be anysuitable polyolefin, such as a polypropylene, a polyethylene, apolybutylene, a poly(4-methyl-1-pentene), and a poly(vinyl cyclohexane).In a preferred embodiment, the thermoplastic polymer is a polyolefinselected from the group consisting of polypropylene homopolymers (e.g.,atactic polypropylene homopolymer, isotactic polypropylene homopolymer,and syndiotactic polypropylene homopolymer), polypropylene copolymers(e.g., polypropylene random copolymers), polypropylene impactcopolymers, and mixtures thereof. Suitable polypropylene copolymersinclude, but are not limited to, random copolymers made from thepolymerization of propylene in the presence of a comonomer selected fromthe group consisting of ethylene, but-1-ene (i.e., 1-butene), andhex-1-ene (i.e., 1-hexene). In such polypropylene random copolymers, thecomonomer can be present in any suitable amount, but typically ispresent in an amount of less than about 10 wt. % (e.g., about 1 to about7 wt. %). Suitable polypropylene impact copolymers include, but are notlimited to, those produced by the addition of a copolymer selected fromthe group consisting of ethylene-propylene rubber (EPR),ethylenepropylene-diene monomer (EPDM), polyethylene, and plastomers toa polypropylene homopolymer or polypropylene random copolymer. In suchpolypropylene impact copolymers, the copolymer can be present in anysuitable amount, but typically is present in an amount of from about 5to about 25 wt. %. The polyolefin polymers described above can bebranched or cross-linked, such as the branching or cross-linking thatresults from the addition of additives that increase the melt strengthof the polymer.

In one embodiment, the thermoplastic polymer contains polypropylenehomopolymers, polypropylene random copolymers, polypropylene impactcopolymers and mixtures thereof. As noted above, the additivecompositions of the invention are particularly useful in the nucleationof polyolefins, such as polypropylene polymers. Thus, in another seriesof embodiments, the invention provides a polymer composition comprisinga polymer and an additive composition as described herein. The polymercomposition can comprise any suitable polymer.

In another preferred embodiment, the thermoplastic polymer can be apolyethylene. Suitable polyethylenes include, but are not limited to,low density polyethylene, linear low density polyethylene, mediumdensity polyethylene, high density polyethylene, and combinationsthereof. In certain preferred embodiments, the thermoplastic polymer isselected from the group consisting of linear low density polyethylene,high density polyethylene, and mixtures thereof. In another preferredembodiment, the thermoplastic polymer is a high density polyethylene.

The high density polyethylene polymers suitable for use in the inventiongenerally have a density of greater than about 0.940 g/cm³. There is noupper limit to the suitable density of the polymer, but high densitypolyethylene polymers typically have a density that is less than about0.980 g/cm³ (e.g., less than about 0.975 g/cm³).

The high density polyethylene polymers suitable for use in the inventioncan be either homopolymers or copolymers of ethylene with one or moreα-olefins. Suitable α-olefins include, but are not limited to, 1-butene,1-hexene, 1-octene, 1-decene, and 4-methyl-1-pentene. The comonomer canbe present in the copolymer in any suitable amount, such as an amount ofabout 5% by weight or less (e.g., about 3 mol. % or less). As will beunderstood by those of ordinary skill in the art, the amount ofcomonomer suitable for the copolymer is largely driven by the end usefor the copolymer and the required or desired polymer propertiesdictated by that end use.

The high density polyethylene polymers suitable for use in the inventioncan be produced by any suitable process. For example, the polymers canbe produced by a free radical process using very high pressures asdescribed, for example, in U.S. Pat. No. 2,816,883 (Larchar et al.), butthe polymers typically are produced in a “low pressure” catalyticprocess. In this context, the term “low pressure” is used to denoteprocesses carried out at pressures less than 6.9 MPa (e.g., 1,000 psig),such as 1.4-6.9 MPa (200-1,000 psig). Examples of suitable low pressurecatalytic processes include, but are not limited to, solutionpolymerization processes (i.e., processes in which the polymerization isperformed using a solvent for the polymer), slurry polymerizationprocesses (i.e., processes in which the polymerization is performedusing a hydrocarbon liquid in which the polymer does not dissolve orswell), gas-phase polymerization processes (e.g., processes in which thepolymerization is performed without the use of a liquid medium ordiluent), or a staged reactor polymerization process. The suitablegas-phase polymerization processes also include the so-called “condensedmode” or “super-condensed mode” processes in which a liquid hydrocarbonis introduced into the fluidized-bed to increase the absorption of theheat producing during the polymerization process. In these condensedmode and super-condensed mode processes, the liquid hydrocarbontypically is condensed in the recycle stream and reused in the reactor.The staged reactor processes can utilize a combination of slurry processreactors (tanks or loops) that are connected in series, parallel, or acombination of series or parallel so that the catalyst (e.g., chromiumcatalyst) is exposed to more than one set of reaction conditions. Stagedreactor processes can also be carried out by combining two loops inseries, combining one or more tanks and loops in series, using multiplegas-phase reactors in series, or a loop-gas phase arrangement. Becauseof their ability to expose the catalyst to different sets of reactorconditions, staged reactor processes are often used to producemultimodal polymers, such as those discussed below. Suitable processesalso include those in which utilize a pre-polymerization step isperformed. In this pre-polymerization step, the catalyst typically isexposed to the cocatalyst and ethylene under mild conditions in asmaller, separate reactor, and the polymerization reaction is allowed toproceed until the catalyst comprises a relatively small amount (e.g.,about 5% to about 30% of the total weight) of the resulting composition.This pre-polymerized catalyst is then introduced to the large-scalereactor in which the polymerization is to be performed.

The high density polyethylene polymers suitable for use in the inventioncan be produced using any suitable catalyst or combination of catalysts.Suitable catalysts include transition metal catalysts, such as supportedreduced molybdenum oxide, cobalt molybdate on alumina, chromium oxide,and transition metal halides. Chromium oxide catalysts typically areproduced by impregnating a chromium compound onto a porous, high surfacearea oxide carrier, such as silica, and then calcining it in dry air at500-900° C. This converts the chromium into a hexavalent surfacechromate ester or dichromate ester. The chromium oxide catalysts can beused in conjunction with metal alkyl cocatalysts, such as alkyl boron,alkyl aluminum, alkyl zinc, and alkyl lithium. Supports for the chromiumoxide include silica, silica-titania, silica-alumina, alumina, andaluminophosphates. Further examples of chromium oxide catalysts includethose catalysts produced by depositing a lower valent organochromiumcompound, such as bis(arene) Cr⁰, allyl Cr²⁺ and Cr³⁺, beta stabilizedalkyls of Cr²⁺ and Cr⁴⁺, and bis(cyclopentadienyl) Cr²⁺, onto a chromiumoxide catalyst, such as those described above. Suitable transition metalcatalysts also include supported chromium catalysts such as those basedon chromocene or a silylchromate (e.g., bi(trisphenylsilyl)chromate).These chromium catalysts can be supported on any suitable high surfacearea support such as those described above for the chromium oxidecatalysts, with silica typically being used. The supported chromiumcatalysts can also be used in conjunction with cocatalysts, such as themetal alkyl cocatalysts listed above for the chromium oxide catalysts.Suitable transition metal halide catalysts include titanium (Ill)halides (e.g., titanium (Ill) chloride), titanium (IV) halides (e.g.,titanium (IV) chloride), vanadium halides, zirconium halides, andcombinations thereof. These transition metal halides are often supportedon a high surface area solid, such as magnesium chloride. The transitionmetal halide catalysts are typically used in conjunction with analuminum alkyl cocatalyst, such as trimethylaluminum (i.e., Al(CH₃)₃) ortriethylaluminum (i.e., Al(C₂H₅)₃). These transition metal halides mayalso be used in staged reactor processes. Suitable catalysts alsoinclude metallocene catalysts, such as cyclopentadienyl titanium halides(e.g., cyclopentadienyl titanium chlorides), cyclopentadienyl zirconiumhalides (e.g., cyclopentadienyl zirconium chlorides), cyclopentadienylhafnium halides (e.g., cyclopentadienyl hafnium chlorides), andcombinations thereof. Metallocene catalysts based on transition metalscomplexed with indenyl or fluorenyl ligands are also known and can beused to produce high density polyethylene polymers suitable for use inthe invention. The catalysts typically contain multiple ligands, and theligands can be substituted with various groups (e.g., n-butyl group) orlinked with bridging groups, such as —CH₂CH₂— or >SiPh₂. The metallocenecatalysts typically are used in conjunction with a cocatalyst, such asmethyl aluminoxane (i.e., (Al(CH₃)_(x)O_(y))_(n). Other cocatalystsinclude those described in U.S. Pat. No. 5,919,983 (Rosen et al.), U.S.Pat. No. 6,107,230 (McDaniel et al.), U.S. Pat. No. 6,632,894 (McDanielet al.), and U.S. Pat. No. 6,300,271 (McDaniel et al). Other “singlesite” catalysts suitable for use in producing high density polyethyleneinclude diimine complexes, such as those described in U.S. Pat. No.5,891,963 (Brookhart et al.).

The high density polyethylene polymers suitable for use in the inventioncan have any suitable molecular weight (e.g., weight average molecularweight). For example, the weight average molecular weight of the highdensity polyethylene can be from 20,000 g/mol to about 1,000,000 g/molor more. As will be understood by those of ordinary skill in the art,the suitable weight average molecular weight of the high densitypolyethylene will depend, at least in part, on the particularapplication or end use for which the polymer is destined. For example, ahigh density polyethylene polymer intended for blow molding applicationscan have a weight average molecular weight of about 100,000 g/mol toabout 1,000,000 g/mol. A high density polyethylene polymer intended forpipe applications or film applications can have a weight averagemolecular weight of about 100,000 g/mol to about 500,000 g/mol. A highdensity polyethylene polymer intended for injection molding applicationscan have a weight average molecular weight of about 20,000 g/mol toabout 80,000 g/mol. A high density polyethylene polymer intended forwire insulation applications, cable insulation applications, tapeapplications, or filament applications can have a weight averagemolecular weight of about 80,000 g/mol to about 400,000 g/mol. A highdensity polyethylene polymer intended for rotomolding applications canhave a weight average molecular weight of about 50,000 g/mol to about150,000 g/mol.

The high density polyethylene polymers suitable for use in the inventioncan also have any suitable polydispersity, which is defined as the valueobtained by dividing the weight average molecular weight of the polymerby the number average molecular weight of the polymer. For example, thehigh density polyethylene polymer can have a polydispersity of greaterthan 2 to about 100. As understood by those skilled in the art, thepolydispersity of the polymer is heavily influenced by the catalystsystem used to produce the polymer, with the metallocene and other“single site” catalysts generally producing polymers with relatively lowpolydispersity and narrow molecular weight distributions and the othertransition metal catalysts (e.g., chromium catalysts) producing polymerwith higher polydispersity and broader molecular weight distributions.The high density polyethylene polymers suitable for use in the inventioncan also have a multimodal (e.g., bimodal) molecular weightdistribution. For example, the polymer can have a first fraction havinga relatively low molecular weight and a second fraction having arelatively high molecular weight. The difference between the weightaverage molecular weight of the fractions in the polymer can be anysuitable amount. In fact, it is not necessary for the difference betweenthe weight average molecular weights to be large enough that twodistinct molecular weight fractions can be resolved using gel permeationchromatography (GPC). However, in certain multimodal polymers, thedifference between the weight average molecular weights of the fractionscan be great enough that two or more distinct peaks can be resolved fromthe GPC curve for the polymer. In this context, the term “distinct” doesnot necessarily mean that the portions of the GPC curve corresponding toeach fraction do not overlap but is merely meant to indicate that adistinct peak for each fraction can be resolved from the GPC curve forthe polymer. The multimodal polymers suitable for use in the inventioncan be produced using any suitable process. As noted above, themultimodal polymers can be produced using staged reactor processes. Onesuitable example would be a staged solution process incorporating aseries of stirred tanks. Alternatively, the multimodal polymers can beproduced in a single reactor using a combination of catalysts each ofwhich is designed to produce a polymer having a different weight averagemolecular weight.

The high density polyethylene polymers suitable for use in the inventioncan have any suitable melt index. For example, the high densitypolyethylene polymer can have a melt index of about 0.01 dg/min to about80 dg/min. As with the weight average molecular weight, those ofordinary skill in the art understand that the suitable melt index forthe high density polyethylene polymer will depend, at least in part, onthe particular application or end use for which the polymer is destined.Thus, for example, a high density polyethylene polymer intended for blowmolding applications can have a melt index of about 0.01 dg/min to about1 dg/min. A high density polyethylene polymer intended for blown filmapplications can have a melt index of about 0.5 dg/min to about 3dg/min. A high density polyethylene polymer intended for cast filmapplications can have a melt index of about 2 dg/min to about 10 dg/min.A high density polyethylene polymer intended for pipe applications canhave a melt index of about 0.02 dg/min to about 0.8 dg/min. A highdensity polyethylene polymer intended for injection molding applicationscan have a melt index of about 2 dg/min to about 80 dg/min. A highdensity polyethylene polymer intended for rotomolding applications canhave a melt index of about 0.5 dg/min to about 10 dg/min. A high densitypolyethylene polymer intended for tape applications can have a meltindex of about 0.2 dg/min to about 4 dg/min. A high density polyethylenepolymer intended for filament applications can have a melt index ofabout 1 dg/min to about 20 dg/min. The melt index of the polymer ismeasured using ASTM Standard D1238-04c.

The high density polyethylene polymers suitable for use in the inventiongenerally do not contain high amounts of long-chain branching. The term“long-chain branching” is used to refer to branches that are attached tothe polymer chain and are of sufficient length to affect the rheology ofthe polymer (e.g., branches of about 130 carbons or more in length). Ifdesired for the application in which the polymer is to be used, the highdensity polyethylene polymer can contain small amounts of long-chainbranching. However, the high density polyethylene polymers suitable foruse in the invention typically contain very little long-chain branching(e.g., less than about 1 long-chain branch per 10,000 carbons, less thanabout 0.5 long-chain branches per 10,000 carbons, less than about 0.1long-chain branches per 10,000 carbons, or less than about 0.01long-chain branches per 10,000 carbons).

The medium density polyethylene polymers suitable for use in theinvention generally have a density of about 0.926 g/cm³ to about 0.940g/cm³. The term “medium density polyethylene” is used to refer topolymers of ethylene that have a density between that of high densitypolyethylene and linear low density polyethylene and contain relativelyshort branches, at least as compared to the long branches present in lowdensity polyethylene polymers produced by the free radicalpolymerization of ethylene at high pressures.

The medium density polyethylene polymers suitable for use in theinvention generally are copolymers of ethylene and at least oneα-olefin, such as 1 butene, 1-hexene, 1-octene, 1-decene, and4-methyl-1-pentene. The α-olefin comonomer can be present in anysuitable amount, but typically is present in an amount of less thanabout 8% by weight (e.g., less than about 5 mol %). As will beunderstood by those of ordinary skill in the art, the amount ofcomonomer suitable for the copolymer is largely driven by the end usefor the copolymer and the required or desired polymer propertiesdictated by that end use.

The medium density polyethylene polymers suitable for use in theinvention can be produced by any suitable process. Like the high densitypolyethylene polymers, the medium density polyethylene polymerstypically are produced in “low pressure” catalytic processes such as anyof the processes described above in connection with the high densitypolyethylene polymers suitable for use in the invention. Examples ofsuitable processes include, but are not limited to, gas-phasepolymerization processes, solution polymerization processes, slurrypolymerization processes, and staged reactor processes. Suitable stagedreactor processes can incorporate any suitable combination of thegas-phase, solution, and slurry polymerization processes describedabove. As with high density polyethylene polymers, staged reactorprocesses are often used to produce multimodal polymers.

The medium density polyethylene polymers suitable for use in theinvention can be produced using any suitable catalyst or combination ofcatalysts. For example, the polymers can be produced using Zieglercatalysts, such as transition metal (e.g., titanium) halides or estersused in combination with organoaluminum compounds (e.g.,triethylaluminum). These Ziegler catalysts can be supported on, forexample, magnesium chloride, silica, alumina, or magnesium oxide. Themedium density polyethylene polymers suitable for use in the inventioncan also be produced using so-called “dual Ziegler catalysts,” whichcontain one catalyst species for dimerizing ethylene into 1-butene(e.g., a combination of a titanium ester and triethylaluminum) andanother catalyst for copolymerization of ethylene and the generated1-butene (e.g., titanium chloride supported on magnesium chloride). Themedium density polyethylene polymers suitable for use in the inventioncan also be produced using chromium oxide catalysts, such as thoseproduced by depositing a chromium compound onto a silica-titaniasupport, oxidizing the resulting catalyst in a mixture of oxygen andair, and then reducing the catalyst with carbon monoxide. These chromiumoxide catalysts typically are used in conjunction with cocatalysts suchas trialkylboron or trialkylaluminum compounds. The chromium oxidecatalysts can also be used in conjunction with a Ziegler catalyst, suchas a titanium halide- or titanium ester-based catalyst. The mediumdensity polyethylene polymers suitable for use in the invention can alsobe produced using supported chromium catalysts such as those describedabove in the discussion of catalysts suitable for making high densitypolyethylene. The medium density polyethylene polymers suitable for usein the invention can also be produced using metallocene catalysts.Several different types of metallocene catalysts can be used. Forexample, the metallocene catalyst can contain a bis(metallocene) complexof zirconium, titanium, or hafnium with two cyclopentadienyl rings andmethylaluminoxane. As with the catalysts used in high densitypolyethylene production, the ligands can be substituted with variousgroups (e.g., n-butyl group) or linked with bridging groups. Anotherclass of metallocene catalysts that can be used are composed ofbis(metallocene) complexes of zirconium or titanium and anions ofperfluorinated boronaromatic compounds. A third class of metallocenecatalysts that can be used are referred to as constrained-geometrycatalysts and contain monocyclopentadienyl derivatives of titanium orzirconium in which one of the carbon atoms in the cyclopentadienyl ringis linked to the metal atom by a bridging group. These complexes areactivated by reacting them with methylaluminoxane or by forming ioniccomplexes with noncoordinative anions, such as B(C₆F₅)₄— orB(C₆F₅)₃CH₃—. A fourth class of metallocene catalysts that can be usedare metallocene-based complexes of a transition metal, such as titanium,containing one cyclopentadienyl ligand in combination with anotherligand, such as a phosphinimine or —O—SiR₃. This class of metallocenecatalyst is also activated with methylaluminoxane or a boron compound.Other catalysts suitable for use in making the linear low densitypolyethylene suitable for use in the invention include, but are notlimited to, the catalysts disclosed in U.S. Pat. No. 6,649,558.

The medium density polyethylene polymers suitable for use in theinvention can have any suitable compositional uniformity, which is aterm used to describe the uniformity of the branching in the copolymermolecules of the polymer. Many commercially-available medium densitypolyethylene polymers have a relatively low compositional uniformity inwhich the high molecular weight fraction of the polymer containsrelatively little of the α-olefin comonomer and has relatively littlebranching while the low molecular weight fraction of the polymercontains a relatively high amount of the α-olefin comonomer and has arelatively large amount of branching. Alternatively, another set ofmedium density polyethylene polymers have a relatively low compositionaluniformity in which the high molecular weight fraction of the polymercontains a relatively high amount of the α-olefin comonomer while thelow molecular weight fraction of the polymer contains relatively littleof the α-olefin comonomer. The compositional uniformity of the polymercan be measured using any suitable method, such as temperature risingelution fractionation.

The medium density polyethylene polymers suitable for use in theinvention can have any suitable molecular weight. For example, thepolymer can have a weight average molecular weight of about 50,000 g/molto about 200,000 g/mol. As will be understood by those of ordinary skillin the art, the suitable weight average molecular weight of the mediumdensity polyethylene will depend, at least in part, on the particularapplication or end use for which the polymer is destined.

The medium density polyethylene polymers suitable for use in theinvention can also have any suitable polydispersity. Many commerciallyavailable medium density polyethylene polymers have a polydispersity ofabout 2 to about 30. The medium density polyethylene polymers suitablefor use in the invention can also have a multimodal (e.g., bimodal)molecular weight distribution. For example, the polymer can have a firstfraction having a relatively low molecular weight and a second fractionhaving a relatively high molecular weight. As with the high densitypolyethylene polymers suitable for use in the invention, the differencebetween the weight average molecular weight of the fractions in themultimodal medium density polyethylene polymer can be any suitableamount. In fact, it is not necessary for the difference between theweight average molecular weights to be large enough that two distinctmolecular weight fractions can be resolved using gel permeationchromatography (GPC). However, in certain multimodal polymers, thedifference between the weight average molecular weights of the fractionscan be great enough that two or more distinct peaks can be resolved fromthe GPC curve for the polymer. In this context, the term “distinct” doesnot necessarily mean that the portions of the GPC curve corresponding toeach fraction do not overlap, but is merely meant to indicate that adistinct peak for each fraction can be resolved from the GPC curve forthe polymer. The multimodal polymers suitable for use in the inventioncan be produced using any suitable process. As noted above, themultimodal polymers can be produced using staged reactor processes. Onesuitable example would be a staged solution process incorporating aseries of stirred tanks. Alternatively, the multimodal polymers can beproduced in a single reactor using a combination of catalysts each ofwhich is designed to produce a polymer having a different weight averagemolecular weight

The medium density polyethylene polymers suitable for use in theinvention can have any suitable melt index. For example, the mediumdensity polyethylene polymer can have a melt index of about 0.01 dg/minto about 200 dg/min. As with the weight average molecular weight, thoseof ordinary skill in the art understand that the suitable melt index forthe medium density polyethylene polymer will depend, at least in part,on the particular application or end use for which the polymer isdestined. Thus, for example, a medium density polyethylene polymerintended for blow molding applications or pipe applications can have amelt index of about 0.01 dg/min to about 1 dg/min. A medium densitypolyethylene polymer intended for blown film applications can have amelt index of about 0.5 dg/min to about 3 dg/min. A medium densitypolyethylene polymer intended for cast film applications can have a meltindex of about 2 dg/min to about 10 dg/min. A medium densitypolyethylene polymer intended for injection molding applications canhave a melt index of about 6 dg/min to about 200 dg/min. A mediumdensity polyethylene polymer intended for rotomolding applications canhave a melt index of about 4 dg/min to about 7 dg/min. A medium densitypolyethylene polymer intended for wire and cable insulation applicationscan have a melt index of about 0.5 dg/min to about 3 dg/min. The meltindex of the polymer is measured using ASTM Standard D1238-04c.

The medium density polyethylene polymers suitable for use in theinvention generally do not contain a significant amount of long-chainbranching. For example, the medium density polyethylene polymerssuitable for use in the invention generally contain less than about 0.1long-chain branches per 10,000 carbon atoms (e.g., less than about 0.002long-chain branches per 100 ethylene units) or less than about 0.01long-chain branches per 10,000 carbon atoms.

The linear low density polyethylene polymers suitable for use in theinvention generally have a density of 0.925 g/cm³ or less (e.g., about0.910 g/cm³ to about 0.925 g/cm³). The term “linear low densitypolyethylene” is used to refer to lower density polymers of ethylenehaving relatively short branches, at least as compared to the longbranches present in low density polyethylene polymers produced by thefree radical polymerization of ethylene at high pressures.

The linear low density polyethylene polymers suitable for use in theinvention generally are copolymers of ethylene and at least oneα-olefin, such as 1-butene, 1-hexene, 1-octene, 1-decene, and4-methyl-1-pentene. The α-olefin comonomer can be present in anysuitable amount, but typically is present in an amount of less thanabout 6 mol. % (e.g., about 2 mol % to about 5 mol %). As will beunderstood by those of ordinary skill in the art, the amount ofcomonomer suitable for the copolymer is largely driven by the end usefor the copolymer and the required or desired polymer propertiesdictated by that end use.

The linear low density polyethylene polymers suitable for use in theinvention can be produced by any suitable process. Like the high densitypolyethylene polymers, the linear low density polyethylene polymerstypically are produced in “low pressure” catalytic processes such as anyof the processes described above in connection with the high densitypolyethylene polymers suitable for use in the invention. Suitableprocesses include, but are not limited to, gas-phase polymerizationprocesses, solution polymerization processes, slurry polymerizationprocesses, and staged reactor processes. Suitable staged reactorprocesses can incorporate any suitable combination of the gas-phase,solution, and slurry polymerization processes described above. As withhigh density polyethylene polymers, staged reactor processes are oftenused to produce multimodal polymers.

The linear low density polyethylene polymers suitable for use in theinvention can be produced using any suitable catalyst or combination ofcatalysts. For example, the polymers can be produced using Zieglercatalysts, such as transition metal (e.g., titanium) halides or estersused in combination with organoaluminum compounds (e.g.,triethylaluminum). These Ziegler catalysts can be supported on, forexample, magnesium chloride, silica, alumina, or magnesium oxide. Thelinear low density polyethylene polymers suitable for use in theinvention can also be produced using so-called “dual Ziegler catalysts,”which contain one catalyst species for dimerizing ethylene into 1-butene(e.g., a combination of a titanium ester and triethylaluminum) andanother catalyst for copolymerization of ethylene and the generated1-butene (e.g., titanium chloride supported on magnesium chloride). Thelinear low density polyethylene polymers suitable for use in theinvention can also be produced using chromium oxide catalysts, such asthose produced by depositing a chromium compound onto a silica-titaniasupport, oxidizing the resulting catalyst in a mixture of oxygen andair, and then reducing the catalyst with carbon monoxide. These chromiumoxide catalysts typically are used in conjunction with cocatalysts suchas trialkylboron or trialkylaluminum compounds. The chromium oxidecatalysts can also be used in conjunction with a Ziegler catalyst, suchas a titanium halide- or titanium ester-based catalyst. The linear lowdensity polyethylene polymers suitable for use in the invention can alsobe produced using supported chromium catalysts such as those describedabove in the discussion of catalysts suitable for making high densitypolyethylene. The linear low density polyethylene suitable for use inthe invention can also be produced using metallocene catalysts. Severaldifferent types of metallocene catalysts can be used. For example, themetallocene catalyst can contain a bis(metallocene) complex ofzirconium, titanium, or hafnium with two cyclopentadienyl rings andmethylaluminoxane. As with the catalysts used in high densitypolyethylene production, the ligands can be substituted with variousgroups (e.g., n-butyl group) or linked with bridging groups. Anotherclass of metallocene catalysts that can be used are composed ofbis(metallocene) complexes of zirconium or titanium and anions ofperfluorinated boronaromatic compounds. A third class of metallocenecatalysts that can be used are referred to as constrained-geometrycatalysts and contain monocyclopentadienyl derivatives of titanium orzirconium in which one of the carbon atoms in the cyclopentadienyl ringis linked to the metal atom by a bridging group. These complexes areactivated by reacting them with methylaluminoxane or by forming ioniccomplexes with noncoordinative anions, such as B(C₆F₅)₄— orB(C₆F₅)₃CH₃—. A fourth class of metallocene catalysts that can be usedare metallocene-based complexes of a transition metal, such as titanium,containing one cyclopentadienyl ligand in combination with anotherligand, such as a phosphinimine or —O—SiR₃. This class of metallocenecatalyst is also activated with methylaluminoxane or a boron compound.Other catalysts suitable for use in making the linear low densitypolyethylene suitable for use in the invention include, but are notlimited to, the catalysts disclosed in U.S. Pat. No. 6,649,558.

The linear low density polyethylene polymers suitable for use in theinvention can have any suitable compositional uniformity, which is aterm used to describe the uniformity of the branching in the copolymermolecules of the polymer. Many commercially-available linear low densitypolyethylene polymers have a relatively low compositional uniformity inwhich the high molecular weight fraction of the polymer containsrelatively little of the α-olefin comonomer and has relatively littlebranching while the low molecular weight fraction of the polymercontains a relatively high amount of the α-olefin comonomer and has arelatively large amount of branching. Alternatively, another set oflinear low density polyethylene polymers have a relatively lowcompositional uniformity in which the high molecular weight fraction ofthe polymer contains a relatively high amount of the α-olefin comonomerwhile the low molecular weight fraction of the polymer containsrelatively little of the α-olefin comonomer. The compositionaluniformity of the polymer can be measured using any suitable method,such as temperature rising elution fractionation.

The linear low density polyethylene polymers suitable for use in theinvention can have any suitable molecular weight. For example, thepolymer can have a weight average molecular weight of about 20,000 g/molto about 250,000 g/mol. As will be understood by those of ordinary skillin the art, the suitable weight average molecular weight of the linearlow density polyethylene will depend, at least in part, on theparticular application or end use for which the polymer is destined.

The linear low density polyethylene polymers suitable for use in theinvention can also have any suitable polydispersity. Many commerciallyavailable linear low density polyethylene polymers have a relativelynarrow molecular weight distribution and thus a relatively lowpolydispersity, such as about 2 to about 5 (e.g., about 2.5 to about 4.5or about 3.5 to about 4.5). The linear low density polyethylene polymerssuitable for use in the invention can also have a multimodal (e.g.,bimodal) molecular weight distribution. For example, the polymer canhave a first fraction having a relatively low molecular weight and asecond fraction having a relatively high molecular weight. As with thehigh density polyethylene polymers suitable for use in the invention,the difference between the weight average molecular weight of thefractions in the multimodal linear low density polyethylene polymer canbe any suitable amount. In fact, it is not necessary for the differencebetween the weight average molecular weights to be large enough that twodistinct molecular weight fractions can be resolved using gel permeationchromatography (GPC). However, in certain multimodal polymers, thedifference between the weight average molecular weights of the fractionscan be great enough that two or more distinct peaks can be resolved fromthe GPC curve for the polymer. In this context, the term “distinct” doesnot necessarily mean that the portions of the GPC curve corresponding toeach fraction do not overlap, but is merely meant to indicate that adistinct peak for each fraction can be resolved from the GPC curve forthe polymer. The multimodal polymers suitable for use in the inventioncan be produced using any suitable process. As noted above, themultimodal polymers can be produced using staged reactor processes. Onesuitable example would be a staged solution process incorporating aseries of stirred tanks. Alternatively, the multimodal polymers can beproduced in a single reactor using a combination of catalysts each ofwhich is designed to produce a polymer having a different weight averagemolecular weight

The linear low density polyethylene polymers suitable for use in theinvention can have any suitable melt index. For example, the linear lowdensity polyethylene polymer can have a melt index of about 0.01 dg/minto about 200 dg/min. As with the weight average molecular weight, thoseof ordinary skill in the art understand that the suitable melt index forthe linear low density polyethylene polymer will depend, at least inpart, on the particular application or end use for which the polymer isdestined. Thus, for example, a linear low density polyethylene polymerintended for blow molding applications or pipe applications can have amelt index of about 0.01 dg/min to about 1 dg/min. A linear low densitypolyethylene polymer intended for blown film applications can have amelt index of about 0.5 dg/min to about 3 dg/min. A linear low densitypolyethylene polymer intended for cast film applications can have a meltindex of about 2 dg/min to about 10 dg/min. A linear low densitypolyethylene polymer intended for injection molding applications canhave a melt index of about 6 dg/min to about 200 dg/min. A linear lowdensity polyethylene polymer intended for rotomolding applications canhave a melt index of about 4 dg/min to about 7 dg/min. A linear lowdensity polyethylene polymer intended for wire and cable insulationapplications can have a melt index of about 0.5 dg/min to about 3dg/min. The melt index of the polymer is measured using ASTM StandardD1238-04c.

The linear low density polyethylene polymers suitable for use in theinvention generally do not contain a significant amount of long-chainbranching. For example, the linear low density polyethylene polymerssuitable for use in the invention generally contain less than about 0.1long-chain branches per 10,000 carbon atoms (e.g., less than about 0.002long-chain branches per 100 ethylene units) or less than about 0.01long-chain branches per 10,000 carbon atoms.

The low density polyethylene polymers suitable for use in the inventiongenerally have a density of less than 0.935 g/cm³ and, in contrast tohigh density polyethylene, medium density polyethylene and linear lowdensity polyethylene, have a relatively large amount of long-chainbranching in the polymer.

The low density polyethylene polymers suitable for use in the inventioncan be either ethylene homopolymers or copolymers of ethylene and apolar comonomer. Suitable polar comonomers include, but are not limitedto, vinyl acetate, methyl acrylate, ethyl acrylate, and acrylic acid.These comonomers can be present in any suitable amount, with comonomercontents as high as 20% by weight being used for certain applications.As will be understood by those skilled in the art, the amount ofcomonomer suitable for the polymer is largely driven by the end use forthe polymer and the required or desired polymer properties dictated bythat end use.

The low density polyethylene polymers suitable for use in the inventioncan be produced using any suitable process, but typically the polymersare produced by the free-radical initiated polymerization of ethylene athigh pressure (e.g., about 81 to about 276 MPa) and high temperature(e.g., about 130 to about 330° C.). Any suitable free radical initiatorcan be used in such processes, with peroxides and oxygen being the mostcommon. The free-radical polymerization mechanism gives rise toshort-chain branching in the polymer and also to the relatively highdegree of long-chain branching that distinguishes low densitypolyethylene from other ethylene polymers (e.g., high densitypolyethylene and linear low density polyethylene). The polymerizationreaction typically is performed in an autoclave reactor (e.g., a stirredautoclave reactor), a tubular reactor, or a combination of such reactorspositioned in series.

The low density polyethylene polymers suitable for use in the inventioncan have any suitable molecular weight. For example, the polymer canhave a weight average molecular weight of about 30,000 g/mol to about500,000 g/mol. As will be understood by those of ordinary skill in theart, the suitable weight average molecular weight of the low densitypolyethylene will depend, at least in part, on the particularapplication or end use for which the polymer is destined. For example, alow density polyethylene polymer intended for blow molding applicationscan have a weight average molecular weight of about 80,000 g/mol toabout 200,000 g/mol. A low density polyethylene polymer intended forpipe applications can have a weight average molecular weight of about80,000 g/mol to about 200,000 g/mol. A low density polyethylene polymerintended for injection molding applications can have a weight averagemolecular weight of about 30,000 g/mol to about 80,000 g/mol. A lowdensity polyethylene polymer intended for film applications can have aweight average molecular weight of about 60,000 g/mol to about 500,000g/mol.

The low density polyethylene polymers suitable for use in the inventioncan have any suitable melt index. For example, the low densitypolyethylene polymer can have a melt index of about 0.2 to about 100dg/min. As noted above, the melt index of the polymer is measured usingASTM Standard D1238-04c.

As noted above, one of the major distinctions between low densitypolyethylene and other ethylene polymers is a relatively high degree oflong-chain branching within the polymer. The low density polyethylenepolymers suitable for use in the invention can exhibit any suitableamount of long-chain branching, such as about 0.01 or more long-chainbranches per 10,000 carbon atoms, about 0.1 or more long-chain branchesper 10,000 carbon atoms, about 0.5 or more long-chain branches per10,000 carbon atoms, about 1 or more long-chain branches per 10,000carbon atoms, or about 4 or more long-chain branches per 10,000 carbonatoms. While there is not a strict limit on the maximum extent oflong-chain branching that can be present in the low density polyethylenepolymers suitable for use in the invention, the long-chain branching inmany low density polyethylene polymers is less than about 100 long-chainbranches per 10,000 carbon atoms.

Thermoplastics have been utilized in a variety of end-use applications,including storage containers, medical devices, food packages, plastictubes and pipes, shelving units, and the like. Such base compositions,however, must exhibit certain physical characteristics in order topermit widespread use. Specifically within polyolefins, for example,uniformity in arrangement of crystals upon crystallization is anecessity to provide an effective, durable, and versatile polyolefinarticle. In order to achieve such desirable physical properties, it hasbeen known that certain compounds and compositions provide nucleationsites for polyolefin crystal growth during molding or fabrication.Generally, compositions containing such nucleating compounds crystallizeat a much faster rate than un-nucleated polyolefin. Such compounds andcompositions that provide faster and or higher polymer crystallizationtemperatures are popularly known as nucleators. Such compounds providenucleation sites for crystal growth during cooling of a thermoplasticmolten formulation.

In one embodiment, the extrusion composition and masterbatch compositioncontain at least one phosphate ester-based nucleating agent provided inthe composition. For the extrusion composition, the phosphateester-based nucleating agent is preferably at a use level of betweenabout 0.01 and 0.15 parts by weight, in relation to 100 parts by weightof the resin. In another embodiment, up to about 0.3 parts of thephosphate ester-based nucleating agent may be used. For the masterbatchcomposition, the phosphate ester-based nucleating agent is preferably ata use level of between about 1 and 30 parts by weight, in relation to100 parts by weight of the resin. In another embodiment, between about 5and 20 parts of the phosphate ester-based nucleating agent may be usedin the masterbatch composition.

The phosphate ester-based nucleating agent can be any suitable phosphateester-based nucleating agent and in an amount suitable to the resin tobe nucleated and the end use.

Phosphate esters suitable for use as the nucleating and/or clarifyingagent include, but are not limited to, sodium2,2′-methylene-bis-(4,6-di-tert-butylphenyl)phosphate (from Asahi DenkaKogyo K.K., known as “NA-11n”), aluminum hydroxy bis2,2′-methylene-bis-(4,6-di-tert-butylphenyl) phosphate (from Asahi DenkaKogyo K.K., known as NA-21™), and other such phosphate esters asdisclosed for example in U.S. Pat. Nos. 5,342,868 and 4,463,113. NA-11is a sodium phosphate ester with the following chemical:

Also useful is NA-21™ which is a blend of aluminum phosphate ester andlithium myristate with the chemical formula aluminumbis[2,2′-methylene-bis-(4,6-di-tert-butylphenyl)phosphate] and NA-27™(also by Asahi Denka Kogyo K.K.) which is a blend of sodium phosphateester-salt and lithium 12-hydroxystearate

In another embodiment, the extrusion composition and masterbatchcomposition contain at least one benzoic acid salt-based nucleatingagent provided in the composition. For the extrusion composition, thebenzoic acid salt-based nucleating agent is preferably at a use level ofbetween about 0.01 and 0.15 parts by weight, in relation to 100 parts byweight of the resin. In another embodiment, up to about 0.3 parts of thebenzoic acid salt-based nucleating agent may be used. For themasterbatch composition, the benzoic acid salt-based nucleating agent ispreferably at a use level of between about 1 and 30 parts by weight, inrelation to 100 parts by weight of the resin. In another embodiment,between about 5 and 20 parts of the benzoic acid salt-based nucleatingagent may be used in the masterbatch composition.

Benzoic acid salt-based nucleating agents may also be used. The type andamount of the benzoic acid salt-based nucleating agent depends on theresin and desired end use properties. As particles distributed within amatrix, non-melting nucleating agents create multiple single pointnucleation sites for crystallized regions to grow around. Suitablenucleating agents include sodium benzoate which has the followingchemical structure:

Lithium benzoate has the following chemical structure:

A benzoic acid salt-based nucleating agent may also have substituents onthe aromatic ring. An example of a substituted benzoic acid nucleatingagent is sodium 4-[(4-chlorobenzoyl)amino] benzoate. More informationabout benzoic acid salt-based nucleators can be found in U.S. Pat. Nos.9,580,575 and 9,193,845, which are herein incorporated by reference.

Preferably, the benzoic acid salt-based nucleating agent is a sodiumbenzoate, lithium benzoate, para-substituted benzoic acid salt or blendsthereof.

The composition (both the extrusion and masterbatch compositions)contain at least one co-additive selected from the group consisting ofpoly(ethylene glycol) and copolymers containing segments of ethyleneoxide, wherein the co-additive has a number average molecular weight ofabout 300 or more. For the extrusion composition the use level of thisco-additive is preferably about 0.005 parts by weight or more, inrelation to 100 parts by weight of the resin. In another embodiment, theco-additive is less than about 5% by weight of the extrusioncomposition. In another embodiment, the co-additive is between about0.01% and about 5% by weight of the extrusion composition. For themasterbatch composition, the use level of this co-additive is preferablyabout 0.5 parts by weight or more, in relation to 100 parts by weight ofthe resin. In another embodiment, the co-additive is less than about 5%by weight of the masterbatch composition. In another embodiment, theco-additive is between about 0.01% and about 5% by weight of themasterbatch composition

In one embodiment, the co-additive is selected from the group consistingof (a) poly(ethylene glycol) and their derivatives like poly(ethyleneglycol) alkyl ether, poly(ethylene glycol) alkyl ester; (b) copolymerscontaining segments of ethylene oxide, such as block copolymers ofethylene oxide and propylene oxide, block copolymers of poly(ethyleneglycol) and another polymer such as, but not limited to, polyethylene,polypropylene, polystyrene, poly(dimethylsiloxane), or polycaprolactone.In one embodiment, the co-additive has an average molecular weight of300 g/mol, or more. In other applications of the invention, theco-additive has an average molecular weight of between 400 and10,000,000 g/mol, more preferably between about 600 and 10,000 g/mol,more preferably between about 300 and 10,000 g/mol.

PEG's (polyethylene glycol's) general chemical structure is usuallyrepresented as follows:

where ‘n’ is the repeating unit. The value of ‘n’ determines themolecular weight of the polymer. Such structure is also termed PEO(poly(ethylene oxide)) when molecular weight is high.

PEGs are used commercially in numerous applications and are availablefrom several manufacturers, for example, PEGs are manufactured by DowChemical under the tradename Carbowax for industrial use, and CarbowaxSentry for food and pharmaceutical use. They vary in consistency fromliquid to solid, depending on the molecular weight, as indicated by anumber following the name.

Poloxamers are nonionic triblock copolymers composed of a centralhydrophobic chain of polyoxypropylene (poly(propylene oxide)) flanked bytwo hydrophilic chains of polyoxyethylene (poly(ethylene oxide)). Theword poloxamer was coined by the inventor, Irving Schmolka, who receivedthe patent for these materials in 1973 (U.S. Pat. No. 3,740,421).Poloxamers are also known by the trade names SYNPERONICS™, PLURONICS™,and KOLLIPHOR™. The PLURONIC™ types are block copolymers based onethylene oxide and propylene oxide available from BASF. They canfunction as antifoaming agents, wetting agents, dispersants, thickeners,and emulsifiers.

Phase separation between soluble clarifiers like diacetals of sorbitoland xylitol and the PP matrix can be enhanced by the use of selectiveco-additives like PEGs and Poloxamers, as demonstrated by Xu, et. al, inU.S. Pat. No. 8,022,133 B2. These co-additives favor the phaseseparation, therefore kicking the soluble clarifier crystals out of thePP earlier and at lower loadings. This effect allows for improvedclarifying function of such clarifiers at relatively low loadings(improved low-level efficacy). This mechanism of phase separation canexplain the improvements for soluble clarifiers but would not beapplicable when using particulate clarifiers or nucleating agents whichdo not dissolve in the polymer matrix. Though many prior art referenceshave disclosed the presence of PEG's as additional compounds likeinternal lubricants in polyolefin compositions, or as interfacial agentsin fluoropolymers, none of the prior art references known to date havedisclosed using this type of co-additives in combination withparticulate nucleating agents showing improvements to the nucleationeffect and thus improved mechanical properties of polyolefincompositions.

The present work shows that when adding different types of PEG's orpoloxamers at loadings as low as 50 ppm (0.005% weight) and up to 2.5%weight, together with different particulate nucleating agents likephosphate ester salts and benzoic acid salts, further flexural modulus(stiffness) improvements are obtained, ranging between 3 and 12% higher,depending on the loadings of the nucleating agent and the polyolefinused.

In one embodiment, the at least one phosphate ester-based nucleatingagent or at least one benzoic salt-based nucleating agent and the atleast one co-additive selected from the group consisting ofpoly(ethylene glycol) and copolymers containing segments of ethyleneoxide are part of a combined additive package, often called anon-dusting blend or one-pack. A one-pack is a composition of a numberof individual components (additives), typically three or four, althoughany number from one to six or seven (or more) can be used. They arebased upon the concept that the lowest melting component acts as abinder, or carrier, for the other components. The one-pack can alsocontain additives such as (but not limited to) anti-oxidantcompositions, stabilizers, and acid scavengers. The one-pack containsadditives with little to no carrier resin being necessary, allowing highconcentration of active ingredients. The one-pack is commonly a fulladditive formulation in one pellet or granule.

The extrusion composition can be used in any suitable thermoplasticprocessing system to create finished goods (which may include pellets,granules, or any other form that is used for an additional extrusionprocess). Some example processes include injection molding, extrusionblow molding (EBM), blow molding, injection stretch blow molding (ISBM),and sheet extrusion-thermoforming.

A basic principle of injection molding is the ability of a thermoplasticto be softened by heating and forced under pressure into a mold cavitythat is clamped together. The result is a thermoplastic that issolidified into the shape of the mold, thus creating the part. Resinpellets may be poured into a feed hopper, a large open bottomedcontainer, which feeds the pellets down to the screw. As a motor turnsthe screw, the pellets are moved forward where they undergo extremepressure and friction which, along with heaters around the screw,generate the heat that melts the pellets. Back pressure can be suppliedfrom a hydraulic pump, to the screw as it melts the plastic to applymore energy resulting in more mixing of the melted plastic. The meltedresin is forced out the other end of the cylinder through a nozzle(injection process) into a relatively cool mold, held closed by theclamping mechanism. The melt cools and hardens, and the mold opens,ejecting the molded part. Injection molding is widely used formanufacturing a variety of parts, from the smallest component to entirebody panels of cars, for example.

In extrusion blow molding, plastic is melted and extruded into a hollowtube (called a parison). The parison is then captured by closing it intoa cooled metal mold. Pressurized air is blown into the parison,inflating it into the shape of the mold. After the plastic has cooledsufficiently, the mold is opened and the part is ejected.

Blow molding is intended for use in manufacturing hollow plastic parts.Its main advantage is the ability to produce hollow shapes withouthaving to join two or more separately molded parts. Examples of partsmade by the EBM process include dairy containers, shampoo bottles, andhollow industrial parts such as drums. Extrusion is the process ofcompacting and melting a plastic material and forcing it through anorifice in a continuous fashion. Material is moved through the heatedmachine barrel by a helical screw (or screws), where it is heated andmixed to a homogeneous state and then forced through a die of the shaperequired for the finished product.

In the injection stretch blow molding process, the plastic is firstmolded into a preform using the injection molding process then stretchedand blown into a bottle. This process can take place all in one stage,or the process can be two stages, with the preform being allowed to coolbetween the stages. In the two-stage system, the molded preforms arereheated (typically using infrared heaters) and stretched with a corerod while the bottles are being blown in two pressure stages. Thestretching of some polymers results in strain hardening of the resin,allowing the bottles to resist deforming under the pressure formed bycarbonated beverages. The main applications of this method are bottles,jars, and other containers.

Thermoforming is a process of forming thermoplastic sheet or film into apart. The sheet or film passes between heaters to its formingtemperatures, then it is stretched over or into atemperature-controlled, single surface mold. The sheet is held againstthe mold surface until cooled, and then the formed part is trimmed fromthe sheet. The sheet can be formed to the contours of a mold bymechanical means (e.g., tools, plus, solid molds, etc.) or pneumaticmeans (e.g., pulling a vacuum or pushing with compressed air). Examplesof thermoformed products are plastic or foam dinnerware, cups, meat andproduce trays, egg cartons, refrigerator liners, computer housings,interior and exterior automotive parts, blisters for packaging, andothers.

EXAMPLES

The following examples further illustrate the subject matter describedabove but, of course, should not be construed as in any way limiting thescope thereof. The following methods, unless noted, were used todetermine the properties described in the following examples.

Each of the compositions was compounded by blending the componentseither using a Henschel high intensity mixer for about 2 minutes with ablade speed of about 2100 rpm, or low intensity mixed in a closedcontainer for approximately one minute.

The compositions were then melt compounded using two methods:

Method 1 (for PP Homopolymers), using a DeltaPlast single-screwextruder, with a 25 mm diameter screw and a length to diameter ratio of30:1. The barrel temperature of the extruder was ramped from 200 to 230°C. and a die temperature of 230° C.; the screw speed was set at about130 rpm.

Method 2 (for the PP impact copolymers), using a Leistritz ZSE-18co-rotating, fully intermeshing, parallel, twin-screw extruder with a 18mm screw diameter and a length/diameter ratio of 40:1. The barreltemperature of the extruder was ranged from approximately 165° C. toapproximately 175° C., the screw speed was set at approximately 500 rpm,the feed rate was 5 kg/hour resulting in a melt temperature ofapproximately 192° C.

The extrudate (in the form of a strand) for each polypropylenecomposition was cooled in a water bath and subsequently pelletized.

The pelletized compositions were then used to form plaques and bars byinjection molding on a 40 ton Arburg injection molder with a 25.4 mmdiameter screw.

50 mils plaques were molded with the different samples at 230° C. barreltemperature, injection speed: 2.4 cc/sec, backpressure: 7 bars, cooling:21° C., cycle time: 27 sec. Samples were submitted to DSC analysis andoptical properties were checked.

ISO shrinkage plaques were molded at 210° C. barrel temperature, targetmolding temp.: 200° C., injection speed: 38.4 cc/sec, backpressure: 7bars, cooling: 40° C., cycle time: 60 sec. Their dimensions are about 60mm long, 60 mm wide and 2 mm thick.

ISO flex bars were molded at 210° C. barrel temperature, injectionspeed: 23.2 cc/sec, backpressure: 7 bars, cooling: 40° C., cycle time:60.05 sec. The resulting bars measured approximately 80 mm long,approximately 10 mm wide, and approximately 4.0 mm thick. The flexuralmodulus was measured.

Differential scanning calorimetry was performed following ASTM E794 inorder to measure Peak Tc and ΔH of crystallization. DSC was measuredusing a Mettler Toledo DSC 700 with Perkin Elmer vented pans and lids.Briefly, an approximately 2.1 to 2.2 mg is heated from 50° C. to 220° C.at 20° C./minute until the sample reaches 220° C. The sample is thenheld at 220° C. for 2 minutes to ensure complete melting before coolingto 50° C. at 20° C./minute. The difference in energy between the sampleand an empty control pan is measured on both the heating and cooling.

Haze of the plaques was measured using a BYK-Gardner Haze meter,according to ASTM 1003. The lower the haze, the better the opticalproperties of the tested parts.

Flexural modulus strength for the bars was measured according to ISOmethod 178.

Heat deflection temperature (HDT) for the bars was measured according toISO method 75, condition: 0.45 MPa.

The notched Izod impact strength for the bars was measured according toISO method 180/A. The notched Izod impact strength was measured at +23°C. on bars that had been conditioned at +23° C.

Example 1

The following example demonstrates the modification of a homopolymer PPcomposition and performance enhancements achieved, according to onemethod of the present invention.

Fourteen homopolymer compositions were produced as described in Tables 1and 2, below

TABLE 1 Homopolymer polypropylene formulations. Component LoadingPolypropylene homopolymer Balance (PROFAX ™ 6301) Stabilizer 1(IRGANOX ® 1010) 500 ppm Stabilizer 2 (IRGAFOS ® 168) 1000 ppm  AcidScavenger (Calcium Stearate) 400 ppm PEG1000 (using a 1% PEG1000 MB inSee Table 2 a 35 MFR PP RCP carrier resin) Nucleator See Table 2 Thepolypropylene used in these examples is PROFAX ™ 6301, which is a 12 MFRPP homopolymer, available from LyondellBasell Industries. IRGANOX ® 1010is a primary antioxidant available from BASF. IRGAFOS ® 168 is asecondary antioxidant available from BASF. Calcium stearate is an acidscavenger available from PMC Biogenix. PEG1000 is a Polyethylene glycolwith average molecular weight of 1000 g/mol. Commercial examples of thismaterial is CARBOWAX SENTRY Polyethylene Glycol 1000 NF available fromthe Dow Chemical Company. When added in the formulation, the targetloading of PEG1000 is 100 ppm. The nucleating agents used in theseexamples are ADK STAB NA-21, NA-11, NA-27 available from Adeka.Nucleating Agent 1 (N.A.1) - blend of calciumcyclohexane-1,2-dicarboxylate and zinc stearate. Nucleating Agent 2(N.A.2) - disodium bicyclo[2.2.1]heptane-2,3-dicarboxylate.

TABLE 2 Homopolymer polypropylene formulations. 1% PEG1000 MB NA-21NA-11 NA-27 N.A.1 N.A.2 Sample (%) (ppm) (ppm) (ppm) (ppm) (ppm) CS1CS1A 1 2 1000 2A 1 1000 3 1000 3A 1 1000 4 1000 4A 1 1000 5 1000 5A 11000 6 1000 6A 1 1000

Each of the compositions listed in Tables 1 and 2 were high intensitymixed, single screw extruded, and pelletized according to the abovedescribed procedure. The resulting pellets were used to injection moldplaques and bars, which were tested for optical properties, flexuralmodulus and thermal properties as described above. The examples with thesame numbers (for example 4 and 4A) had the same compositions, but the Aexample included PEG1000.

TABLE 3 Mechanical and thermal properties of formulations. Haze wasmeasured using a 50 mils plaque. Haze Chord Increase Increase Increasediffer- Mod- in mod- in mod- Tc in Tc Haze ence ulus ulus ulus Sample (°C.) (° C.) (%) (% units) (MPa) (MPa) (%) CS1 115.8 57.3 1374 CS1A 116.00.2 58.8 +1.5 1377 3 0.0 2 126.3 26.9 1598 2A 127.2 0.9 23.8 −3.1 167577 4.8 3 127.8 37.9 1650 3A 128.7 0.9 37.3 −0.6 1768 118 7.2 4 128.833.4 1779 4A 128.8 0 33.8 +0.4 1801 22 1.2 5 124.3 37.8 1552 5A 124.50.2 36.7 −1.1 1537 −15 0.0 6 128.7 37.8 1783 6A 128.0 −0.7 40.4 +2.61760 −23 0.0

The difference calculations in Table 3 are between the numbered sample(for example 4) and the same numbered sample with an A (for example 4A).As expected, with the addition of 100 ppm PEG1000, the crystallizationtemperature (Tc) and flexural modulus do not significantly improve, andthe haze increased as shown in CS1 and CS1A. Table 3 also shows thatwhen adding nucleating agents to this homopolymer, the Tc and flexuralmodulus increased, and the haze decreased as expected. The addition ofPEG1000 did not affect the Tc or the flexural modulus in a significantway for the nucleated samples 5, and 6, as shown when comparing sample 5with 5A, and sample 6 with 6A. Surprisingly, PEG1000 shows a synergisticeffect with the nucleating agents present in samples 2, 3 and 4(phosphate ester salts), imparting a higher increase in flexural modulusand some improvement to the Tc as is shown in Table 3. Comparing sample2 to 2A, sample 3 to 3a and sample 4 to 4A, the flexural modulusincreases by 77, 118 and 22 MPa, respectively.

Example 2

The following example demonstrates the modification of a heterophasic PPcopolymer composition and performance enhancements achieved, accordingto the method of the present invention.

Seven heterophasic PP copolymer compositions were produced as describedin Tables 3 and 4, below

TABLE 4 Heterophasic polypropylene copolymer formulations. ComponentLoading Heterophasic PP copolymer Balance (INEOS ™ 500-GA20) Stabilizer1 (IRGANOX ® 1010) 500 ppm Stabilizer 2 (IRGAFOS ® 168) 1000 ppm  AcidScavenger (DHT-4A) 400 ppm PEG1000 (using a 1% PEG1000 MB in See Table 5a 25 MFR PP RCP carrier resin) Nucleator See Table 5 The polypropyleneused in these examples is INEOS ™ 500-GA-20, which is a 20 MFRheterophasic PP copolymer. IRGANOX ® 1010 is a primary antioxidantavailable from BASF IRGAFOS ® 168 is a secondary antioxidant availablefrom BASF DHT-4A is a hydrotalcite used as acid scavenger, availablefrom Kisuma Chemicals. PEG1000 is a Polyethylene glycol with averagemolecular weight of 1000 g/mol. Commercial examples of this material isCARBOWAX SENTRY ™ Polyethylene Glycol 1000 NF available from the DowChemical Company. When added in the formulation, the target loading ofPEG1000 is 100 ppm. The nucleating agents used in these examples are ADKSTAB NA-21, NA-11, NA-71 available from Adeka.

TABLE 5 Heterophasic polypropylene copolymer formulations. 1% PEG1000 MBNA-11 NA-21 NA-71 Sample (%) (ppm) (ppm) (ppm) CS8  9 1000  9A 1 1000 101000 10A 1 1000 11 1000 11A 1 1000

Each of the compositions listed in Tables 4 and 5 were high intensitymixed, twin screw extruded, and pelletized according to the abovedescribed procedure. The resulting pellets were used to injection moldbars which were tested for HDT, flexural modulus and thermal propertiesas described above.

TABLE 6 Mechanical and thermal properties of formulations. ChordIncrease Increase Increase Increase Mod- in mod- in mod- Tc in Tc HDT inHDT ulus ulus ulus Sample (° C.) (° C.) (° C.) (° C.) (MPa) (MPa) (%)CS8 111.7 73.3 1091  9 124.2 80.8 1212  9A 124.6 0.4 83.7 2.9 1264 524.3 10 122.6 80.0 1271 10A 124.3 1.7 83.0 3.0 1319 48 3.8 11 124.6 83.31274 11A 125.8 1.5 85.7 2.4 1326 52 4.1

As expected, when adding nucleating agents to this heterophasicpolypropylene, the Tc, HDT and flexural modulus increased. The additionof PEG1000 shows a synergistic effect with the nucleating agents,imparting a higher increase in HDT and flexural modulus and someimprovement to the Tc as is shown in Table 3. Comparing sample 9 to 9A,the HDT increased 3° and the flexural modulus increased 52 MPa,comparing sample 10 to sample 10a the HDT increased 3° and the flexuralmodulus increased 48 MPa and comparing sample 11 to 11A, the HDTincreased 2.4° and the flexural modulus increased 52 MPa. This exampleconfirms that the synergistic effect between the PEG and the nucleatingagents is present not only in a homopolymer PP but also in aheterophasic PP copolymer. This example also shows that the effect ispresent when using a different type of acid scavenger.

Example 3

The following example demonstrates the modification of a homopolymer PPcomposition and performance enhancements achieved according to themethod of the present invention. In this example, a different type ofPEG and a different type of acid scavenger were used.

Eight homopolymer compositions were produced as described in Tables 7and 8, below

TABLE 7 Homopolymer polypropylene formulations. Component LoadingPolypropylene (PROFAX ™ 6301) Balance Stabilizer 1 (IRGANOX ® 1010) 500ppm Stabilizer 2 (IRGAFOS ® 168) 1000 ppm  Acid Scavenger (DHT-4V) 400ppm PEG3350 See Table 8 Nucleator See Table 8 The homopolymerpolypropylene used in these examples is PROFAX ™ 6301, which is a 12 MFRPP homopolymer available from LyondellBasell Industry. DHT-4V is ahydrotalcite used as acid scavenger available from Kisuma Chemicals.PEG3350 is a Polyethylene glycol with average molecular weight of 3350g/mol. Commercial example of this material is CARBOWAX SENTRY ™Polyethylene Glycol 3350 available from the Dow Chemical Company. Thenucleating agents used in these examples are phosphate esters ADK STABNA-21 & NA-11, available from Adeka, and the phosphate ester EustabNA-50 available from Eutec Chemical Co.

TABLE 8 Homopolymer polypropylene formulations. PEG3350 NA-21 NA-50NA-11 Sample (ppm) (ppm) (ppm) (ppm) CS12 CS12A 100 13 1000 13A 100 100014 1000 14A 100 1000 15 1000 15A 100 1000

Each of the compositions listed in Tables 7 and 8 were high intensitymixed, single screw extruded, and pelletized according to the abovedescribed procedure. The resulting pellets were used to form plaques andbars which were tested for optical properties, flexural modulus andthermal properties as described above.

TABLE 9 Thermal, optical and mechanical properties of formulations. Hazewas measured using a 50 mils plaque. Haze Chord Increase IncreaseIncrease differ- Mod- in mod- in mod- Tc in Tc Haze ence ulus ulus ulusSample (° C.) (° C.) (%) (% units) (MPa) (MPa) (%) CS12 117.0 57.9 1311CS12A 116.0 −1.0 59.6 +1.7 1272 −39 −3.0 13 125.7 26.4 1593 13A 127.21.5 22.9 −3.5 1691 98 6.2 14 124.7 30.3 1539 14A 126.5 1.8 24.1 −6.21649 110 7.1 15 129.2 27.6 1695 15A 129.3 0.1 32.0 +4.4 1816 121 7.1

Table 9 shows the performance of the different formulations preparedwith DHT-4V as acid scavenger and adding PEG3350. When comparing thecomparative sample CS12 (un-nucleated homopolymer) with CS12A (theun-nucleated resin with 100 ppm of PEG3350), the crystallizationtemperature, haze and flexural modulus were adversely affected. Asexpected, with the addition of the different nucleating agents, thecrystallization temperature and flexural modulus of the homopolymer PPincreased and the haze decreased (lower haze values are desired).Surprisingly, the samples with nucleating agent showed improvedperformance with the addition of PEG3350, imparting a higher increase inflexural modulus and crystallization temperature (Tc). Comparing sample13 with sample 13A, the Tc increased by 1.5° C., the haze decreased by3.5 units and the flexural modulus increased by 98 MPa (6.2%improvement). Comparing sample 14 with 14A, the Tc increased 1.8° C.,the haze decreased 6.2 units and the flexural modulus increased 110 MPa(7.1% improvement) and comparing sample 15 with sample 15A, the Tc didnot show a significant change, the haze increased 4.4 units and theflexural modulus increased by 121 MPa (7.1% improvement).

Example 4

The following example demonstrates the modification of a homopolymer PPcomposition and performance enhancements achieved according to themethod of the present invention. For this example, a different acidscavenger and the PEG3350 were used.

Eight homopolymer compositions were produced as described in Tables 10and 11, below:

TABLE 10 Homopolymer polypropylene formulations. Component LoadingPolypropylene (PROFAX ™ 6301) Balance Stabilizer 1 (IRGANOX ® 1010) 500ppm Stabilizer 2 (IRGAFOS ® 168) 1000 ppm  Acid Scavenger (CaSt) 400 ppmPEG3350 See Table 11 Nucleator See Table 11 CaSt is Calcium stearate,used as acid scavenger and available from PMC Biogenix. PEG3350 is aPolyethylene glycol with average molecular weight of 3350 g/mol.Commercial example of this material is CARBOWAX SENTRY ™ PolyethyleneGlycol 3350 available from the Dow Chemical Company. The nucleatingagents used in these examples are phosphate esters ADK STAB NA-21 &NA-11, available from Adeka and NA-50 available from Eutec Chemical Co.

TABLE 11 Hompolymer polypropylene formulations. PEG3350 NA-21 NA-50NA-11 Sample (ppm) (ppm) (ppm) (ppm) CS16 CS16A 100 17 1000 17A 100 100018 1000 18A 100 1000 19 1000 19A 100 1000

Each of the compositions listed in Tables 10 and 11 were high intensitymixed, single screw extruded, and pelletized according to the abovedescribed procedure. The resulting pellets were injection molded to formplaques and bars which were tested for optical properties, flexuralmodulus and thermal properties as described above.

TABLE 12 Mechanical, optical and thermal properties of formulations.Haze was measured using a 50 mils plaque. Haze Chord Increase IncreaseIncrease differ- Mod- in mod- in mod- Tc in Tc Haze ence ulus ulus ulusSample (° C.) (° C.) (%) (% units) (MPa) (MPa) (%) CS16 115.5 60.1 1269CS16A 114.5 −1.0 60.0 +0.1 1258 −11 −0.9 17 126.3 25.4 1615 17A 127.2+0.9 23.0 −1.6 1710 95 5.9 18 125.2 28.0 1571 18A 127.2 +2.0 23.1 −4.91686 115 7.3 19 127.5 34.6 1677 19A 128.2 +0.7 34.9 +0.3 1784 107 6.4

Table 12 shows the performance of the different formulations preparedwith calcium stearate as acid scavenger and adding PEG3350. As expectedand shown when comparing CS16 (the un-nucleated homopolymer) with CS16A,the addition of 100 ppm PEG3350 to the polypropylene without nucleatingagents did not improve the crystallization temperature, haze or flexuralmodulus. The samples with the nucleating agent show a synergistic effectwhen PEG3350 is present, imparting a higher increase in flexural modulusand Tc. Comparing sample 17 with 17A, the Tc and Haze improved and theflexural modulus significantly improved by 95 MPa (around 5.9%improvement), comparing sample 18 and 18A, the Tc improved 2° C. and thehaze improved 4.9 units, while the flexural modulus improved 115 MPa(around 7.3% improvement) and comparing samples 19 and 19A, the Tc andHaze showed modest improvements, while the flexural modulus improved by107 MPa (around 6.4% improvement). Example 3 and 4 confirm that thesynergistic effect between PEG and the nucleating agents is presentregardless of the acid scavenger used and the type of PEG used.

Example 5

The following example demonstrates the modification of a homopolymer PPcomposition and performance enhancements achieved according to themethod of the present invention. This example demonstrates the effect ofdifferent loadings of PEG3350 when used in combination with differentloadings of the nucleating agent.

Thirty-seven homopolymer compositions were produced as described inTables 13 and 14, below:

TABLE 13 Homopolymer polypropylene formulations. Component LoadingPolypropylene (PROFAX ™ 6301) Balance Stabilizer 1 (IRGANOX ® 1010) 500ppm Stabilizer 2 (IRGAFOS ® 168) 1000 ppm  Acid Scavenger (DHT-4V) 400ppm PEG3350 See Table 14 Nucleator (NA-21) See Table 14

TABLE 14 Hompolymer polypropylene formulations. PEG3350 NA-21 Sample(ppm) (ppm) CS20 CS20A 50 CS20B 100 CS20C 250 CS20D 500 CS20E 1000 21250 21A 50 250 21B 100 250 21C 250 250 21D 500 250 21E 1000 250 22 50022B 100 500 22C 250 500 22D 500 500 22E 1000 500 23 750 23B 100 750 23C250 750 23D 500 750 23E 1000 750 24 1000 24B 100 1000 24C 250 1000 24D500 1000 24E 1000 1000 24F 2000 1000 24G 5000 1000 24H 10000 1000 24J25000 1000 25 1500 25A 50 1500 25B 100 1500 25C 250 1500 26 2000 26B 1002000

Each of the compositions listed in Tables 13 and 14 were high intensitymixed, single screw extruded, and pelletized according to the abovedescribed procedure. The resulting pellets were injection molded to formplaques and bars, which were tested for optical properties, flexuralmodulus and thermal properties as described above.

TABLE 15 Mechanical, optical and thermal properties of formulations.Haze was measured using a 50 mils plaque. Haze Chord Increase IncreaseIncrease differ- Mod- in mod- in mod- Tc in Tc Haze ence ulus ulus ulusSample (° C.) (° C.) (%) (% units) (MPa) (MPa) (%) CS20 117.0 57.9 1311CS20A 116.0 −1.0 59.6 +1.7 1272 −39 −3.0 CS20B 115.0 −2.0 58.4 +0.5 1265−46 −3.5 CS20C 114.7 −2.3 57.3 −0.6 1267 −44 −3.4 CS20D 114.3 −2.7 57.0−0.9 1255 −56 −4.3 CS20E 114.2 −2.8 57.3 −0.6 1269 −42 −3.2 21 122.033.4 1473 21A 125.0 3.0 31.4 −2.0 1563 90 6.1 21B 124.8 2.8 29.4 −4.01584 111 7.5 21C 125.0 3.0 29.4 −4.0 1587 114 7.7 21D 125.2 3.2 30.0−3.4 1604 131 8.9 21E 125.7 3.7 32.3 −1.1 1619 146 9.9 22 123.5 29.31514 22B 125.3 1.8 25.9 −3.4 1583 69 4.6 22C 125.7 2.2 25.7 −3.6 1624110 7.3 22D 126.2 2.7 26.0 −3.3 1643 129 8.5 22E 126.3 2.8 28.6 −0.71686 172 11.4 23 123.5 30.7 1496 23B 125.5 2.0 25.5 −5.2 1583 87 5.8 23C126.2 2.7 25.3 −5.4 1616 120 8.0 23D 126.5 3.0 25.9 −4.8 1641 145 9.723E 126.8 3.3 28.5 −2.2 1675 179 12.0 24 124.2 27.9 1529 24B 125.7 1.524.3 −3.6 1596 67 4.4 24C 126.3 2.1 24.1 −3.8 1632 103 6.7 24D 126.5 2.324.9 −3.0 1671 142 9.3 24E 127.2 3.0 27.7 −0.2 1687 158 10.3 24F 127.83.6 30.6 +2.7 1710 181 11.8 24G 127.3 3.1 45.4 +17.5 1729 200 13.1 24H127.5 3.3 53.5 +25.6 1715 186 12.2 24J 127.8 3.6 74.7 +46.8 1693 16410.7 25 126.0 23.9 1689 25A 127.0 1.0 21.2 −2.7 1740 51 3.0 25B 127.21.2 21.1 −2.8 1762 73 4.3 25C 127.5 1.5 21.5 −2.4 1786 97 5.7 26 126.721.8 1687 26B 127.3 0.6 20.4 −1.4 1754 67 4.0

Table 15 shows the performance of the different formulations preparedvarying the loading of NA-21 and PEG3350. As shown when comparing CS20(the un-nucleated homopolymer) with CS20A, CS20B, CS20C, CS20D, CS20E,the addition of PEG3350 at different loadings, to the polypropylenewithout nucleating agents, did not improve the crystallizationtemperature, haze or flexural modulus. In fact, higher loadings ofPEG3350 adversely affected the Tc and the flexural modulus. The sampleswith the nucleating agent NA-21 at loadings from 250 to 2000 ppm, show asynergistic effect when PEG3350 is present at loadings between 50 and1000 ppm, and with increasing loadings of PEG3350 increasing Tc andflexural modulus were obtained, with similar or improved haze (lowerhaze values). When adding PEG3350 at levels above 1000 ppm and up to25000 ppm (2.5%), the optical properties (haze) of the resin areadversely affected, but the Tc and flexural modulus continue to showimprovements. Other processing issues start manifesting at these highloadings, like screw slippage, related to the high amount of PEG in thesystem.

Example 6

The following example demonstrates the modification of a heterophasic PPcopolymer composition and performance enhancements achieved according tothe method of the present invention. This example demonstrates theeffect of different loadings of PEG3350 when used in combination withdifferent loadings of the nucleating agent.

Twenty-one heterophasic PP copolymer compositions were produced asdescribed in Tables 16 and 17, below

TABLE 16 Heterophasic polypropylene copolymer formulations. ComponentLoading Polypropylene (REPOL ™ B120MA) Balance Mineral oil (DRAKEOL ™34) 200 ppm PEG3350 See Table 17 Nucleator (NA-21) See Table 17 REPOL ™B120MA is a 12 MFR hetorophasic PP copolymer, available from RelianceIndustries LTD. This is a commercial resin in pellets form which isalready stabilized with acid scavenger and antioxidants. DRAKEOL ™ 34 isa mixture of paraffinic and naphthenic hydrocarbons (mineral oil),available from Calumet Lubricants. PEG3350 is a Polyethylene glycol withaverage molecular weight of 3350 g/mol. Commercial example of thismaterial is CARBOWAX SENTRY ™ Polyethylene Glycol 3350 available fromthe Dow Chemical Company. The nucleating agent used in these examples isADK STAB NA-21, available from Adeka.

TABLE 17 Heterophasic polypropylene copolymer formulations. PEG3350NA-21 Sample (ppm) (ppm) CS27 28 250 28A 100 250 28B 250 250 28C 500 25028D 1000 250 29 500 29A 100 500 29B 250 500 29C 500 500 29D 1000 500 30750 30A 100 750 30B 250 750 30C 500 750 30D 1000 750 31 1000 31A 1001000 31B 250 1000 31C 500 1000 31D 1000 1000

Each of the compositions listed in Tables 16 and 17 were hand mixed in aclose container, twin screw extruded, and pelletized according to theabove described procedure. The resulting pellets were injection moldedto form bars, which were tested for flexural modulus.

TABLE 18 Mechanical properties of formulations. Chord Increase inIncrease in Modulus modulus modulus Sample (MPa) (MPa) (%) CS27 1144 281312 28A 1411 99 7.5 28B 1440 128 9.8 28C 1444 132 10.1 28D 1443 13110.0 29 1378 29A 1451 73 4.2 29B 1439 61 4.4 29C 1494 116 8.4 29D 1498120 8.7 30 1389 30A 1443 54 3.9 30B 1505 116 8.4 30C 1511 122 8.8 30D1530 141 10.2 31 1437 31A 1527 90 6.3 31B 1547 110 7.7 31C 1577 140 9.731D 1545 108 7.5

Table 18 shows the performance of the different formulations preparedvarying the loading of NA-21 and PEG3350 in the heterophasicpolypropylene copolymer. As expected, when adding the nucleating agent,the flexural modulus increased with increasing NA-21 loadings, as can beseen when comparing CS27 with samples 28, 29, 30 and 31. The sampleswith the nucleating agent NA-21 at loadings from 250 to 1000 ppm, show asynergistic effect with the varying loadings of PEG3350. In general,with increasing loading of PEG3350 in the presence of all the differentloadings of NA-21, the flexural modulus increased, as one can see whencomparing sample 28 with 28A, 28B, 28C, 28D, comparing sample 29 with29A, 29B, 29C, 29D, comparing sample 30 with 30A, 30B, 30C, 30D andcomparing sample 31 with 31A, 31B, 31C and 31 D. This example confirmsthat the synergistic effect between PEG3350 and NA-21 are present inboth homopolymer polypropylenes and heterophasic polypropylenecopolymers.

Example 7

The following example demonstrates the modification of a homopolymer PPcomposition and performance enhancements achieved according to themethod of the present invention. This example demonstrates the effect ofdifferent loadings of PLURONIC™ F108 when used in combination withdifferent loadings of the nucleating agent.

Eight homopolymer compositions were produced as described in Tables 19and 20, below:

TABLE 19 Homopolymer polypropylene formulations. Component LoadingPolypropylene (PROFAX ™ 6301) Balance Stabilizer 1 (IRGANOX ® 1010) 500ppm Stabilizer 2 (IRGAFOS ® 168) 1000 ppm  Acid Scavenger (DHT-4V) 400ppm PLURONIC ™ F108 See Table 20 Nucleator (NA-21) See Table 20PLURONIC ™ F108 is a difunctional block copolymer based on ethyleneoxide and propylene oxide available from BASF.

TABLE 20 Homopolymer polypropylene formulations. PLURONIC ™ F108 NA-21Sample (ppm) (ppm) 32 500 32A 100 500 32B 250 500 32C 500 500 33 100033A 100 1000 33B 250 1000 33C 500 1000

Each of the compositions listed in Tables 19 and 20 were high intensitymixed, single screw extruded, and pelletized according to the abovedescribed procedure. The resulting pellets were injection molded to formplaques and bars, which were tested for optical properties, flexuralmodulus and thermal properties as described above.

TABLE 21 Mechanical, optical and thermal properties of formulations.Haze was measured using a 50 mils plaque. Haze Chord Increase IncreaseIncrease differ- Mod- in mod- in mod- Tc in Tc Haze ence ulus ulus ulusSample (° C.) (° C.) (%) (% units) (MPa) (MPa) (%) 32 122.7 31.9 145232A 125.0 2.3 27.4 −4.5 1528 76 5.2 32B 125.3 2.6 26.9 −5.0 1570 118 8.132C 125.5 2.8 27.1 −4.8 1583 131 9.0 33 124.5 26.9 1522 33A 125.7 1.223.5 −3.4 1576 54 3.5 33B 126.0 1.5 22.8 −4.1 1566 44 2.9 33C 126.5 2.023.6 −3.3 1602 80 5.3

Table 21 shows the performance of the different formulations preparedvarying the loading of NA-21 and PLURONIC™ F108. The presence ofPLURONIC™ F108 shows a similar synergistic effect than the PEG's tested.When PLURONIC™ F108 is present at loadings between 100 and 500 ppmtogether with NA-21, increased Tc and flexural modulus were obtained,with improved haze (lower haze values). This can be seen when comparingsample 32 with 32A, 32B, 32C and comparing sample 33 with 33A, 33B and33C.

Example 8

The following example demonstrates the modification of a homopolymer PPcomposition and performance enhancements achieved according to themethod of the present invention. This example used two different typesof nucleating agents and the PEG3350.

Twelve homopolymer compositions were produced as described in Tables 22and 23, below

TABLE 22 Homopolymer polypropylene formulations. Component LoadingPolypropylene (PROFAX ™ 6301) Balance Stabilizer 1 (IRGANOX ® 1010) 500ppm Stabilizer 2 (IRGAFOS ® 168) 1000 ppm  PEG3350 See Table 23Nucleator (NaBz) See Table 23 The nucleating agent used in theseexamples is NaBz (sodium benzoate) available from Emerald KalamaChemical.

TABLE 23 Hompolymer polypropylene formulations. PEG3350 NaBz Sample(ppm) (ppm) 34 500 34A 100 500 34B 250 500 34C 500 500 34D 1000 500 34E2000 500 35 1000 35A 100 1000 35B 250 1000 35C 500 1000 35D 1000 100035E 2000 1000

Each of the compositions listed in Tables 22 and 23 were high intensitymixed, single screw extruded, and pelletized according to the abovedescribed procedure. The resulting pellets were injection molded to formplaques and bars which were tested for optical properties, flexuralmodulus and thermal properties as described above.

TABLE 24 Mechanical, optical and thermal properties of formulations.Haze was measured using a 50 mils plaque. Haze Chord Increase IncreaseIncrease differ- Mod- in mod- in mod- Tc in Tc Haze ence ulus ulus ulusSample (° C.) (° C.) (%) (% units) (MPa) (MPa) (%) 34 125.5 46.8 148034A 126.0 0.5 45.2 −1.6 1531 51 3.4 34B 125.7 0.2 45.8 −1.0 1526 46 3.134C 125.5 0 46.0 −0.8 1534 54 3.6 34D 125.0 −0.5 46.5 −0.3 1514 34 2.334E 124.7 −0.8 48.7 1.9 1510 30 2.0 35 127.5 47.5 1514 35A 127.3 −0.247.4 −0.1 1570 56 3.7 35B 127.2 −0.3 47.6 0.1 1586 72 4.8 35C 126.7 −0.847.1 −0.4 1586 72 4.8 35D 126.3 −1.2 47.7 0.2 1600 86 5.7 35E 126.2 −1.349.4 1.9 1580 66 4.4

Table 24 shows the performance of the different formulations preparedwith sodium benzoate at two different loadings, adding PEG3350 atvarying loadings. When comparing sample 34 with 34A, 34B, 34C, 34D and34E, one can see that the composition with sodium benzoate at 500 ppmshows improved Tc and haze and higher flexural modulus with increasingloading of PEG3350 going from 100 to 500 ppm, and that when adding 1000and 2000 ppm of PEG3350, the Tc, haze and flexural modulus show smallimprovements. When comparing sample 35 with 35A, 35B, 35C, 35D and 35E,one can see that even though the Tc and haze seem to deteriorate. NaBzat 1000 ppm shows improved flexural modulus with increasing loading ofPEG3350.

PE Examples

The following examples further illustrate the subject matter describedabove but, of course, should not be construed as in any way limiting thescope thereof. The following methods, unless noted, were used todetermine the properties described in the following examples.

The polyethylene resins were ground to 35 mesh using a disc attritionmill.

Each of the compositions was compounded by blending the componentseither using a Henschel high intensity mixer for about 2 minutes with ablade speed of about 2100 rpm.

The compositions were then melt compounded using a DeltaPlastsingle-screw extruder, with a 25 mm diameter screw and a length todiameter ratio of 30:1. The barrel temperature of the extruder wasramped from 160 to 180° C. and a die temperature of 180° C.; the screwspeed was set at about 130 rpm.

The extrudate (in the form of a strand) for each polyethylenecomposition was cooled in a water bath and subsequently pelletized.

The pelletized compositions were then used to form plaques and bars byinjection molding on a 40 ton Arburg injection molder with a 25.4 mmdiameter screw.

ISO shrinkage plaques were molded at 210° C. barrel temperature, targetmolding temp.: 200° C., injection speed: 38.4 cc/sec, backpressure: 7bars, cooling: 40° C., cycle time: 60 sec. Their dimensions are about 60mm long, 60 mm wide and 2 mm thick. These plaques were used to measureRecrystallization Temperature and Bi-directional stiffness.

ISO flex bars were molded at 210° C. barrel temperature, injectionspeed: 23.2 cc/sec, backpressure: 7 bars, cooling: 40° C., cycle time:60.05 sec. The resulting bars measured approximately 80 mm long,approximately 10 mm wide, and approximately 4.0 mm thick. The flexuralmodulus and impact resistance were measured.

The peak polymer recrystallization temperature (Tc) for thethermoplastic polymer compositions was measured using a differentialscanning calorimeter (Mettler-Toledo DSC822 differential scanningcalorimeter). In particular, a sample was taken from the target part andheated at a rate of 20° C./minute from a temperature of 60° C. to 220°C., held at 220° C. for two minutes, and cooled at a rate ofapproximately 10° C./minute to a temperature of 60° C. The temperatureat which peak polymer crystal reformation occurred (which corresponds tothe peak polymer recrystallization temperature) was recorded for eachsample.

Flexural properties testing (reported as 1% secant modulus) wasperformed on the above-mentioned plaques using an MTS Q-Test-5instrument with a span of 32 mm, a fixed deflection rate of 8.53mm/minute, and a nominal sample width of 50.8 mm. Samples were preparedby cutting square sections (approximately 50 mm×50 mm) from the centersof the plaques to obtain an isotropically sized sample. In addition totesting the samples across the machine/flow direction as is customary(labeled as “Transverse Direction” in the results Table), samples werealso tested by flexing across the transverse direction to flow tomeasure stiffness in that direction as well (labeled as “MachineDirection” in the results Table) in order to examine the bi-directionalstiffness of the plaques.

The notched Izod impact strength for the bars was measured according toISO method 180/A. The notched Izod impact strength was measured at +23°C. on bars that had been conditioned at +23° C.

Example 9

The following example demonstrates the modification of a high densitypolyethylene composition and performance enhancements achieved,according to the method of the present invention. This example usedcalcium stearate as the acid scavenger and one type of polyethyleneglycol, added using a concentrate.

Eight polyethylene compositions were produced as described in Tables 25and 26, below:

TABLE 25 High density polyethylene formulations. Component Loading HDPE(Dow DMDA-8007) Balance Stabilizer 1 (IRGANOX ® 1010) 500 ppm Stabilizer2 (IRGAFOS ® 168) 1000 ppm  Acid Scavenger (CaSt) 400 ppm PEG1000 (usinga 1% PEG1000 MB in See Table 26 a 35 MFR PP RCP carrier resin) NucleatorSee Table 26 The high density polyethylene used in these examples is DowDMDA-8007, which is an 8.3 MI2.16, 0.967 g/cm³ polyethylene, availablefrom The Dow Chemical Company. IRGANOX ® 1010 is a primary antioxidantavailable from BASF IRGAFOS ® 168 is a secondary antioxidant availablefrom BASF Calcium stearate is an acid scavenger available from PMCBiogenix. PEG1000 is a Polyethylene glycol with average molecular weightof 1000 g/mol. Commercial example of this material is CARBOWAX SENTRY ™Polyethylene Glycol 1000 NF available from the Dow Chemical Company.Nucleating Agent 1 (N.A.1) - blend of calciumcyclohexane-1,2-dicarboxylate and zinc stearate. Nucleating Agent 2(N.A.2) - disodium bicyclo[2.2.1]heptane-2,3-dicarboxylate. NucleatingAgent 4 (N.A.3) - blend containing sodium4-[(4-chlorobenzoyl)amino]benzoate as the main component

TABLE 26 High density polyethylene formulations. 1% PEG1000 MB N.A.3N.A.1 N.A.2 Sample (%) (ppm) (ppm) (ppm) CS36 CS36A 1 37 1000 37A 1 100038 1000 38A 1 1000 39 1000 39A 1 1000

Once the resin was ground, each of the compositions listed in Tables 25and 26 were high intensity mixed, single screw extruded, and pelletizedaccording to the above described procedure. The resulting pellets wereused to form plaques and bars. which were tested for bi-directionalflexural modulus and thermal properties as described above.

TABLE 27 Mechanical and thermal properties of formulations. MachineIncrease Increase Transverse Increase Increase Direction in MD in MDDirection in TD in TD Increase 1% secant 1% secant 1% secant 1% secant1% secant 1% secant T_(c) in Tc modulus modulus modulus modulus modulusmodulus Sample (° C.) (° C.) (MPa) (MPa) (%) (MPa) (MPa) (%) CS36 119.31035 1072 CS36A 119.0 −0.3 1008 −27 −2.6 1060 −12 −1.1 37 120.7 12971269 37A 120.7 0 1331 34 2.6 1221 −48 −3.8 38 122.0 1130 1539 38A 122.00 1150 20 1.8 1526 −13 −0.1 39 121.2 1101 1527 39A 120.7 −0.5 1079 −22−2.0 1566 39 2.6

Table 27 shows the testing results for the high density polyethyleneformulations. As expected, with the addition of 100 ppm PEG1000 to thehigh density polyethylene, the crystallization temperature and flexuralmodulus do not improve, and impact has an adverse effect, as shown inCS36 and CS36A. Also as expected, when the nucleating agents were added,an increase in the machine direction (MD) flexural modulus and thetransverse direction (TD) flexural modulus was obtained. It is knownthat depending on the type of crystal growth orientation imparted by thenucleating agent, they will impart higher MD flexural modulus (when theyimpart machine direction orientation) or TD flexural modulus (when theyimpart transverse direction orientation). When comparing sample CS36with samples 37, one can see that when adding N.A.3, there is a higherincrease in the MD flexural modulus than in the TD flexural modulus,which indicates that N.A.3 impacts MD crystal growth orientation. Whencomparing CS36 with sample 38, one can see that when adding N.A.1 itimparts a higher increase to the TD flexural modulus compared to the MDflexural modulus, which indicates that N.A.1 imparts TD orientation.When comparing CS36 with sample 39, one can see that when N.A.2 wasadded, a higher increase to the TD flexural modulus compared to the MDflexural modulus was obtained, which indicates that N.A.2 imparts TDorientation. The addition of 100 ppm of PEG1000 to the high densitypolyethylene composition with N.A.3 shows some positive effect on the MDflexural modulus and a negative effect on the TD flexural modulus, asshown when comparing samples 37 and 37A. This is an indication that theaddition of PEG1000 further improves the machine direction orientationimparted by the nucleating agent. The addition of 100 ppm of PEG1000 tothe composition with N.A.1 shows only a small improvement to the MDflexural modulus and no effect on the TD flexural modulus, as shown whencomparing samples 38 and 38A. When adding 100 ppm of PEG1000 to thecomposition containing N.A.2, there is a negative effect on the MDflexural modulus and a positive effect on the TD flexural modulus, asshown on samples 39 and 39A. This is an indication that PEG1000 furtherimproves the TD orientation imparted by N.A.2.

Example 10

The following example demonstrates the modification of a high densitypolyethylene composition and performance enhancements achieved,according to the method of the present invention. This example used adifferent type of acid scavenger and a different type of PEG.

Twenty polyethylene compositions were produced as described in Tables 28and 29, below

TABLE 28 High density polyethylene formulations. Component Loading HDPE(Dow DMDA-8007) Balance Stabilizer 1 (IRGANOX ® 1010) 500 ppm Stabilizer2 (IRGAFOS ® 168) 1000 ppm  Acid Scavenger (DHT-4V) 400 ppm PEG3350 SeeTable 29 Nucleator See Table 29 The high density polyethylene used inthese examples is Dow DMDA-8007, which is an 8.3 MI2.16, 0.967 g/cm³polyethylene, available from The Dow Chemical Company. IRGANOX ® 1010 isa primary antioxidant available from BASF IRGAFOS ® 168 is a secondaryantioxidant available from BASF DHT-4V is a hydrotalcite used as acidscavenger available from Kisuma Chemicals. PEG3350 is a Polyethyleneglycol with average molecular weight of 3350 g/mol. Commercial exampleof this material is CARBOWAX SENTRY ™ Polyethylene Glycol 3350 availablefrom the Dow Chemical Company. The nucleating agents used in theseexamples are NA-21, NA-11, available from Adeka. Nucleating Agent 1(N.A.1) - blend of calcium cyclohexane-1,2-dicarboxylate and zincstearate. Nucleating Agent 4 (N.A.3) - blend containing sodium4-[(4-chlorobenzoyl)amino]benzoate as the main component

TABLE 29 High density polyethylene formulations. PEG3350 N.A.1 N.A.4NA-21 NA-11 Sample (ppm) (ppm) (ppm) (ppm) (ppm) CS40 41 1000 41A 1001000 41B 250 1000 41C 500 1000 41D 1000 1000 42 1000 42A 100 1000 42B250 1000 42C 500 1000 42D 1000 1000 43 1000 43A 100 1000 43B 250 100043C 500 1000 43D 1000 1000 44 1000 44A 100 1000 44B 250 1000 44C 5001000 44D 1000 1000

Once the resin was ground, each of the compositions listed in Tables 28and 29 were high intensity mixed, single screw extruded, and pelletizedaccording to the above described procedure. The resulting pellets wereused to form plaques and bars. which were tested for bi-directionalflexural modulus and thermal properties as described above.

TABLE 30 Mechanical and thermal properties of formulations. MachineIncrease Increase Transverse Increase Increase Direction in MD in MDDirection in TD in TD Increase 1% secant 1% secant 1% secant 1% secant1% secant 1% secant T_(c) in Tc modulus modulus modulus modulus modulusmodulus Sample (° C.) (° C.) (MPa) (MPa) (%) (MPa) (MPa) (%) CS40 118.81079 1096 41 121.8 982 1477 41A 121.8 0 976 −6 −0.1 1504 27 1.8 41B122.0 0.2 978 −4 0.4 1468 −9 0.6 41C 121.8 0 966 −16 −1.6 1482 5 0.3 41D122.0 0.2 989 7 0.1 1479 2 0.1 42 120.7 1283 1084 42A 120.5 −0.2 1309 262.0 1018 −66 −6.1 42B 120.5 −0.2 1367 84 6.6 1014 −70 −6.5 42C 120.7 01338 55 4.3 1039 −45 −4.2 42D 120.5 −0.2 1334 51 4.0 1028 −56 −5.2 43120.0 1040 1310 43A 120.7 0.7 1063 23 2.2 1330 20 1.5 43B 120.8 0.8 105111 1.1 1372 62 4.7 43C 120.8 0.8 1069 29 2.8 1356 46 3.5 43D 120.8 0.81036 −4 −0.4 1370 60 4.6 44 120.8 988 1387 44A 121.0 0.2 998 10 1.0 148396 6.9 44B 121.0 0.2 984 −4 −0.4 1512 125 9.0 44C 121.2 0.4 1015 27 2.71517 130 9.4 44D 121.2 0.4 1018 30 3.0 1493 106 7.6

Table 30 shows the effect of PEG3350 at varying loadings, when added todifferent nucleating agents. As expected, when adding the differentnucleating agents to the high density polyethylene composition, higherTc and bi-directional flexural modulus was obtained as expected, andshown when comparing CS40 with samples 41, 42, 43, and 44. The samplescontaining N.A.1 did not seem to be affected by the presence of PEG3350,since the Tc and flexural modulus in the two directions did not changemuch, as can be seen comparing sample 41 with 41A, 41B, 41C, and 41 D.When adding PEG3350 to the samples containing N.A.3, comparing sample 42with 42A, 42B, 42C and 42D, one can see that the bi-directional flexuralmodulus changes with the addition of PEG3350, obtaining higher MDflexural modulus and lower TD flexural modulus, which is an indicationof stronger crystal growth orientation. In a similar way, the additionof PEG3350 changes the bi-directional flexural modulus of the samplescontaining NA-21 and NA-11, this time imparting higher TD flexuralmodulus, as can be seen when comparing sample 43 with 43A, 43B, 43C, 43Dand comparing sample 44 with 44A, 44B, 44C and 44D. The results obtainedfor MD and TD flexural modulus indicate that the N.A.3 and the phosphateesters impart different types of orientation. In U.S. Pat. Nos.9,580,575 and 9,193,845 it is shown that the type of orientationimparted by N.A.4 generates lower permeation (oxygen transmission rateand water vapor transmission rate). Adding PEG to N.A.3, furtherreductions in the permeation would be expected. On the other hand, withthe phosphate esters, one would expect the permeation to increase, andcombinations of phosphate esters with PEG should further increase thepermeation. Depending on the end use application, either an increase ordecrease in permeation may provide desirable benefits.

Example 11

The following example demonstrates the modification of a linear lowdensity polyethylene composition and performance enhancements achieved,according to the method of the present invention.

Twenty polyethylene compositions were produced as described in Tables 31and 32, below:

TABLE 31 Linear low density polyethylene formulations. Component LoadingHDPE (DOWLEX ™ 2035) Balance Stabilizer 1 (IRGANOX ® 1010) 500 ppmStabilizer 2 (IRGAFOS ® 168) 1000 ppm  Acid Scavenger (DHT-4V) 400 ppmPEG3350 See Table 32 Nucleator See Table 32 The linear low densitypolyethylene used in these examples is DOWLEX ™ 2035, which is an 6MI2.16, 0.921 g/cm3 polyethylene, available from The Dow ChemicalCompany.

TABLE 32 Linear low density polyethylene formulations. PEG3350 N.A.1N.A.4 NA-21 NA-11 Sample (ppm) (ppm) (ppm) (ppm) (ppm) CS45 46 1000 46A100 1000 46B 250 1000 46C 500 1000 46D 1000 1000 47 1000 47A 100 100047B 250 1000 47C 500 1000 47D 1000 1000 48 1000 48A 100 1000 48B 2501000 48C 500 1000 48D 1000 1000 49 1000 49A 100 1000 49B 250 1000 49C500 1000 49D 1000 1000

Once the resin was ground, each of the compositions listed in Tables 31and 32 were high intensity mixed, single screw extruded, and pelletizedaccording to the above described procedure. The resulting pellets wereused to form plaques and bars. which were tested for bi-directionalflexural modulus and thermal properties as described above.

TABLE 33 Mechanical and thermal properties of formulations. MachineIncrease Increase Transverse Increase Increase Direction in MD in MDDirection in TD in TD Increase 1% secant 1% secant 1% secant 1% secant1% secant 1% secant T_(c) in Tc modulus modulus modulus modulus modulusmodulus Sample (° C.) (° C.) (MPa) (MPa) (%) (MPa) (MPa) (%) CS45 104.7196 204 46 116.3 201 292 46A 116.3 0 206 5 2.5 290 −2 −0.7 46B 116.3 0200 −1 −0.5 288 −4 −1.4 46C 116.3 0 200 −1 −0.5 282 −10 −3.4 46D 116.00.3 202 1 0.5 280 −12 −4.1 47 112.3 219 204 47A 112.3 0 223 4 1.8 196 −8−4.1 47B 112.3 0 221 2 0.9 199 −5 −2.6 47C 112.5 −0.2 217 −2 −0.9 204 00.0 47D 112.3 0 213 −6 −2.7 205 1 0.5 48 114.3 255 278 48A 114.7 −0.4240 −15 −5.9 293 15 5.4 48B 114.8 −0.5 243 −12 −4.7 287 9 3.2 48C 114.8−0.5 236 −19 −7.5 296 18 6.5 48D 114.7 −0.4 238 −17 −6.7 291 13 4.7 49114.3 220 288 49A 114.3 0 232 12 5.5 293 5 1.7 49B 114.3 0 228 8 3.6 2957 2.4 49C 114.2 0.1 227 7 3.2 287 −1 −0.3 49D 114.3 0 218 −2 −0.9 283 −5−1.7

Table 33 shows the effect of PEG3350 at varying loadings, when added todifferent nucleating agents in the linear low density polyethylene. Whenadding the different nucleating agents, higher Tc and bi-directionalflexural modulus was obtained as expected, and shown when comparing CS45with samples 46, 47, 48, AND 49. The samples containing N.A.1 and N.A.3did not seem to be affected by the presence of PEG3350, since the Tc andflexural modulus in the two directions did not change much. When addingPEG3350 to the samples containing NA-21 and NA-11, a more significanteffect is obtained, imparting higher TD flexural modulus in combinationwith NA-21, as can be seen when comparing sample 48 with 48A, 48B, 48C,48D and imparting higher MD flexural modulus in combination with NA-11,as can be seen comparing sample 49 with 49A, 49B, 49C and 49D. Theresults obtained for MD and TD flexural modulus indicate that the N.A.4and the phosphate esters impart different types of orientation. In U.S.Pat. Nos. 9,580,575 and 9,193,845 it is shown that the type oforientation imparted by N.A.3 generates lower permeation (oxygentransmission rate and water vapor transmission rate). Adding PEG toN.A.3 one would expect further reductions in the permeation. On theother hand, with the phosphate esters, one would expect the permeationto increase, and combinations of phosphate esters with PEG shouldfurther increase the permeation.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

What is claimed is:
 1. An extrusion composition comprising: (a) at leastone resin selected from the group consisting of polypropylenehomopolymers, polypropylene random copolymers, and polypropylene impactcopolymers; (b) at least one phosphate ester-based nucleating agentprovided in the composition at a use level of between about 0.01 and0.15 parts by weight, in relation to 100 parts by weight of the resin;(c) at least one co-additive selected from the group consisting ofpoly(ethylene glycol) and copolymers containing segments of ethyleneoxide, wherein the co-additive has a number average molecular weight ofabout 300 or more, and wherein the use level of the co-additive is about0.005 parts by weight or more, in relation to 100 parts by weight of theresin, and; (d) lithium myristate at a use level of between about 0.01and 0.15 parts by weight, in relation to 100 parts by weight of theresin.
 2. The extrusion composition of claim 1, wherein the phosphateester-based nucleating agent comprises an aluminum phosphate ester. 3.The extrusion composition of claim 1, wherein the phosphate ester-basednucleating agent comprises a sodium phosphate ester.
 4. An extrusioncomposition comprising: (a) at least one resin selected from the groupconsisting of polypropylene homopolymers, polypropylene randomcopolymers, and polypropylene impact copolymers; (b) at least onephosphate ester-based nucleating agent provided in the composition at ause level of between about 0.01 and 0.15 parts by weight, in relation to100 parts by weight of the resin; (c) at least one co-additive selectedfrom the group consisting of poly(ethylene glycol) and copolymerscontaining segments of ethylene oxide, wherein the co-additive has anumber average molecular weight of about 300 or more, and wherein theuse level of the co-additive is about 0.005 parts by weight or more, inrelation to 100 parts by weight of the resin, and; (d) lithium12-hydroxystearate at a use level of between about 0.01 and 0.15 partsby weight, in relation to 100 parts by weight of the resin.
 5. Theextrusion composition of claim 1, wherein the co-additive is apoly(ethylene glycol) having a number average molecular weight between300 and about 10,000.
 6. An article of manufacture made from theextrusion composition of claim
 1. 7. The extrusion composition of claim4, wherein the phosphate ester-based nucleating agent comprises analuminum phosphate ester.
 8. The extrusion composition of claim 4,wherein the phosphate ester-based nucleating agent comprises a sodiumphosphate ester.
 9. The extrusion composition of claim 4, wherein theco-additive is a poly(ethylene glycol) having a number average molecularweight between 300 and about 10,000.
 10. An article of manufacture madefrom the extrusion composition of claim 4.